!!!!??? It's happening again!
 

My corals are dying again and this time I have zero explanation for it. Everything was recovering from the carnage in February/March, the system was dialled back in, Everything that survived had healed over and was starting to send out new growth tips and then 2 days ago BAM!

Every single coral that had been losing tissue before is losing tissue again. It's starting at the growth tips, so basically all the recovery they've made since I spent 10 days doing water changes, and two weeks testing the water every single day vanished in 48 hours.

This time I've literally changed nothing. No equipment has changed, no chemicals have changed, nothing about the pellet reactor has changed (it's still got 10% of the pellets in it recommended for a system my size), I'm still on the same pale of salt I was using after everything started growing again. I literally haven't touched the tank in two weeks.

I'm so beyond ready to rip this thing out and turn it in to a closet.

Does anyone in Calgary have a recommendation for a lab to do a full work-up on my water? They only thing I can think is that something is poisoning my corals. I've gone over all my equipment but maybe I'm missing something that's leaching copper or something in to my water?

I'm ready to give up.

Oh man that rly sucks!!! Maybe it in the rocks n leaching out slowly?

Sorry to hear Adam :-(. If you're ready to give up then i would make a suggestion to get rid of your DI. It was causing me issues. I haven't been using DI for over a month now. Worth a shot maybe. Of course, you will still need to do some hefty water chnages again to get out whatever is currently in your tank.

These are long shots but any chance something like a foreign object...maybe a metal clamp in a submerged area or even a penny could have got into the water? Are there power-heads in any of the tanks with magnet attachments that could maybe be rusting?

As in the DI resin on my RO unit? What was yours doing?

I've looked, I can't see anything obvious. the magnets on my MPs are all intact (I replaced one about 6 months ago that was looking worn), and the magnets on the various koralias in my sump all look brand new. That's why I want a commercial lab to test for heavy metals, I just can't figure this out.

The only other thing I can think is alk. While I was doing the water changes and re-setting everything it got as low as 5.5, then over the course of 2 weeks I got it up very slowly back in to the 7-7.5 range. Things started recovering the fastest when it was around 6. I haven't tested it since last weekend, but today it's 8.5. Like last time I'm not sure if the spike was because the corals have stopped growing or if it slowly crept up and caused damage. In any case I turned off the dosing pump to get it to come back down in to the 7s.

My tank is no where near low nutrient at this point though, so even with (a very small amount of ) biopellets on the system, I just can't accept that an alk of 8.5 would cause so much damage.

Params:
Alk: 8.5
Calcium: 415
Mag: 1260
Nitrate: about 2ppm
PO4: 0.11

I hadn't been running GFO for the past two weeks as the pellets weren't kicking in with PO4 levels of 0.008ppm, which is where they sit with the reactor running. The nitrates are finally starting to fall from a high of about 5ppm. Anyone think those numbers would indicate coral damage?

As for rust, that wouldn't do it. I have hose clamps in my sump that have been there for years. Rusted solid. No issues. I also have add magnets get exposed and rust up, again, no issues.

Put one of those color-changing Poly Filter pads in the system and see if it turns any colors.

There was a problem with some carbon, but that was a couple years ago.
http://www.advancedaquarist.com/blog...or-reef-carbon

I think a couple of people here on Canreef ran into that.

Could it be something in your tank releasing toxins (ie. Sea cucumber, injured fish) I've read on Reef Central about people who were having mystery die off and it was found to be an injured critter releasing low enough lvls of toxins to not affect fish/inverts but could hurt coral.

It's a long shot in the dark and I've looked but I can't find the article on Reef Central to link

If I take out my gfo or let it go too long, I lose sps. Exactly the same as what you describe. And I think I mentioned this before, but testing po4 is next to meaningless. I never get a reading that "explains" it. I just know, no gfo = sps losses.

Maybe ditch the pellets for now. I don't think they're doing anything for you.

What about Ferdinand? Could he be releasing a chemical due to stress of some sort? I know box fish can do that. But I have read about mystery die off being an issue with toxins from a critter as well.

It could also help to ditch the pellets and DI like kein and tony said. I would start from the beginning and bring it back to simple.

I also can't remember...are you running a calcium reactor?

Professional aquarium water testing.

http://aquariumwatertesting.com

This is exactly what I think I need, can you get them locally?

I remember this disaster for people, I thankfully avoided it because I almost never run carbon. I actually haven't been running carbon since this all began, though tonight I put some ROX carbon in a bag in my filter sock in case this is somehow an organic toxin.

This thought keeps crossing my mind. I know they produce more ostracitoxin when they're stressed, but if there ever was a fish that seemed un-stressed it's this guy. The only time he looks stressed is when he's doing his belly-against-the-glass fin wiggle when he's decided it's time for me to feed him. I'd re-home him if I could find a tank he'd do well in, but at 10 inches there aren't many of them around. None of my sessile inverts or my other fish have exhibited anything I'd call symptoms of poisoning or illness though, so I'm having a hard time pinning this on him. I added GAC back to the tank tonight on the off chance this is somehow an organic toxin.

And no, no calcium reactor. I've always dosed a three part mix and switched to the tropic Tropic Marin 3 line after this all went to h*ll in March. I thought I had brought it back to basics when this all started, but without dosing my alk drops to deadly levels in 48 hours, and without pellets my nitrates just keep going up. I'm not sure where they'd stabilize, but it was going to be in the many tens of ppm for sure.

It's death at the growth tips? What do you think causes it? I know GFO adsorbs more than just P. Based on this I put the GFO back online tonight as well as the GAC. I feel like those pellets have me by the balls though. Without them, my nitrates rapidly leave the range acceptable for SPS, but I can never rule them out as a cause for this.

Thank you, I'm going to contact them tomorrow.

I think your spot on with the ALK... A swing from 5.5 to 8.5 is pretty big within a couple of weeks. My tank went from 6-8 and I lost several colonies and almost all growth tips were burnt. I opted to stick with reefers best and reef crystals salt due to the low ALK in the mixture. Fluval is very high in ALK which was my problem.

On a side note, I would do some calculations on how much you should be dosing and measure to ensure it's dosing the right amount. After messing with dosing for a couple of months, I dropped it and picked up a calcium reactor. I would never do an SPS tank without one again.

My alk recently went south and I raised it from about 4 to 8 over a few days, no issues with anything burning. Not sure I'd blame alk.

Gfo also messes with your alkalinity not a huge amount but it drops a bit , Randy has it noted and how much roughly it pulls out, this is a concern to sps guys who keep low alk or carbon dose.



I lost most my sps a while back remember to a alk overdose , the climb from 6-9 dkh resulted in rtn and then I pulled the doser the drop caused me as much harm as the raising did.

The cow fish is a concern too I would think.

Do you make your own food? If so Is it Possible that something changed and maybe contaminated?

Sure does seem like something is leaching (or accumulating) in your water. It was corrected for a while with massive water changes, and then came back. You could try the massive water changes again, to see if again that fixes it, at least for a while.

Meanwhile, would keep testing your water. Not sure if our standard copper water tests are granular enough at the low range, but might be worth doing if you have them.

Alk swings are not good, for sure, but hard to believe it would cause RTN to that extent though, and so suddenly. I have had swings between 7 - 9, but no effects that I could see.

And hope you are past that hydrogen sulphide stuff with your pellet reactor. I definitely don't like the recirculating types. As others have said, would ditch that for a while, too, until you can figure out what is going on. Your higher phosphates are not good either, but again, shouldn't have caused the sudden RTN, I don't think.

Anyway, keep us informed on what you find. We all want to learn from this, if we can.

Ive been watching a tank (established for years) do what your is doing since they added biopellets. all sps are receding. what brand are you using?

People tend to underestimate what a change in Alk can really do to a tank especially if you are running Bio Pellets. Whenever my Alk started to approach 8 my tips would burn and I would get STN on my SPS. When I corrected it over a couple days the other way with water changes I sometimes ended up with RTN on some SPS.

+1 on the Alk swings. I've had SPS RTN on me with less of a swing than what you mentioned.

I think for sps keepers this is a very important topic / thread that needs to be followed closely.

Crazy thought but do you use a home cleaning service or anyone in the home spraying anything that you don't know about?

Bulk reef supply. What's head scratching about this is that other than a brief window when I was repairing my biopellet reactor, my tank has never not had biopellets. They've been on the tank longer than I've had any of my corals, so my dinner plate sized colonies grew from frags in a pellet dosed system.

I ordered the kit from the states to do a full panel on my water. I got two so I could send a sample of pre and post water change water. They'll test for all the things we normally test for, as well as copper, iron, and other other trace elements that you couldn't reliably test for with a home hobby kit that could be toxic at high levels. If I can at least eliminate the basic chemistry, I'll know what this isn't. And yah, this reactor isn't long for this world. It's working in as much as nothing is clogged and the pellets are tumbling (so no hydrogen sulphide), but if my water chemistry comes back normal, I'm probably done with pellets for good.

I hope you guys are right, though why now after 2 years the tank would become this sensitive to alkalinity when it's gotten as high as 9 in the past with 10 times the volume of pellets in the reactor with no problems is confusing. I just wish I had a way to be figure out causative relationships and not just correlated ones. My alk would have gone from 7.5 to 8.5 over the course of 8 days (I tested April 26th and again on May 4th), but I don't know if that was a sudden spike or if it gained a bit every day. I also haven't changed the alkalinity settings on the doser since... I think April 12th (that weekend anyway) and the rate the volume in the container has been falling has remained constant. I'm mixing my dosing solution using a scale and carefully measured volumes of RO/DI water, so I'm confident the concentration in the dosing solution has remained constant.

It's possible my doser freaked out and OD'd the tank, but since turning off the alkalinity pump almost 48 hours ago, the dKH in my tank has only fallen from 8.5 to 7.23. That's a shockingly small amount of consumption for my tank. After I did all those massive water changes and things started to heal and grow again, I was losing 1.7dKH every 24 hours without dosing.

I'm presently stuck not being able to tell if the alkalinity spike caused the damage, or if the growth shut down for another reason, which caused the constant amount I think I've been dosing since mid-April to spike the levels. Basically, is it a symptom or is it the cause... Hopefully the commercial tests I'm going to do will help narrow it down.

The dKH has only been below 8 for about 24 hours, so we'll see if things start to improve. Even corals that never got damaged in the first round are damaged now, so at least I have a lot of indicators against which to measure this. If this is an alk/biopellet interaction, oh man that's the end of biopellets for me. not being able to go above 8dKH on threat of total reef collapse is an untenable position to be in, especially considering the amount of warning the corals give me before losing significant percentages of their tissue. The recovery (if any ever happens) to some of my biggest pieces will be measured in years.

I've talked with my cleaning lady at length about this. She closes all the cabinet doors (upper and lower) when she cleans my house, wipes down the outside of the aquarium glass with nothing more than a damp cloth that she then buffs with a dry cloth, and she damp mops the floor with just water. Once a month she'll add a tiny amount of vinegar to the water she uses on the ceramic tiles. The only place she uses solvents that could be dangerous to the tank are in the upstairs bathrooms that get used the most, and she changes her gloves to do that.

do you use vertex?
thats the one they are using in the particular tank. may be a fluke
but it is happenning since they added the vertex biopellets in a reactor

why would "sps guys" purposly keep a low alk tank, alk is one of the main building blocks in coral growth, if anything we would tand to keep it higher.

I agree with Brad, that swing over weeks isn't a factor, but what was you max alk level or do you know. I have seen big tanks done in by Alk burn but it wasn't realy fromt he level just going to high, but rather the Alk up powder not being mixed properly and landing on the corals. kinda looks like the tips start to melt and get stringy. I tried to find some pictures of the sump/dosing set up you have to see the locations you add your stuff, but couldn't find any. you young kids put so much stuff into your tanks now days it makes it hard anyways, GFO, Bioballs, ect....

also another thing is temp, it will do the same thing, have you had any spikes laitly? here is a pic of what temp did to my tank years ago

http://www.members.shaw.ca/crystalk/tankwrek/frags.jpg

it started out with just the tips like an Alk burn then the rest started slughing off here was the end result.



this bucket is 24" accross

http://www.members.shaw.ca/crystalk/...ek/bucket1.jpg

this one is 36" accross

http://www.members.shaw.ca/crystalk/...ek/bucket2.jpg

Steve

Also... hope it is not your cowfish getting a taste of your corals, and then chewing on the SPS tips when he gets hungry...

by low i mean 7-8 obviously not 4 or 5


when running bio pellets or even zeolites(ULNS) it is better to keep it lower

What's in there now is 100% the Bulk Reef Supply brand, though for about a year before this all started there was a blend of Bulk reef supply and Vertex in there.

Those pictures made me feel sick. I would have quit if that happened to me, though I'm headed there just in much slower motion. My Apex logs the temp of my tank but it only stores 7 days at a stretch, I try and download it at least once a week, but I've got a couple of gaps in the month of April. My the highest temp I've got a record for since the beginning of April was 26.5 and my lowest temp was 25.00. It only got up to 26.5 once on a sunny day when I wasn't home so all the windows in the house were closed and my cleaning lady closed all 4 upper cabinet doors (I usually leave the office side doors open to keep my radions cool).

I'm gonna be real honest, he's definitely started doing that to one colony that's been pretty hard hit by all of this and he's not helping at all. However, his chew marks are very distinctive looking, and very different from what's happening to the rest of the corals. When he bites it he leaves the tips looking crushed and tapered, and he's only been biting the tips of that one colony. While growth tips on the rest of them are dying, the skeleton underneath isn't damaged, and in many places there will still be a little bit of tissue right at the tip while a ring around it will die (or just a small chunk of tissue on every single corallite cup will die, making it look like it's been raked over a cheese grater). Most of my stag corals are also losing whole patches of tissue at random places along the branches, in places his mouth couldn't reach if he tried. I work from home right next to the tank as well, so I'm pretty sure I'd see him doing it it if he was causing this much damage.

That one coral he nibbles on handled it no problem before this all started because it's huge and he preferentially chews on one or two branches, but at this point it's half dead. The two issues working together are going to send it over the edge I'm pretty sure. If I could find a good home for this fish, I'd do it, but alas no one seems to want a 10", definitely not reef safe cowfish lol.

I picked up a poly-filter pad and put it against a baffle in my sump so that 100% of the water in my tank has to flow through it. I'm not sure how much heavy metal there needs to be in the water to cause a noticeable colour change, but we'll see what it looks like tomorrow.

I'm in more of an emergency situation than I thought:

http://i1100.photobucket.com/albums/...pse366134b.jpg

I need to start seriously looking in to re-homing some fish here. Testing for ammonia didn't even occur to me because this tank is two years old. All fish alive and accounted for, all inverts alive and accounted for, I haven't changed feeding patterns in months (I actually feed a bit less now)... the only thing I can think is the chemi-clean treatment I did to get the cyano under control after this all got out of hand the first time, but that was in March. If that caused a cycle shouldn't it be done by now? At the very least my corals shouldn't have been growing and improving for the whole month of April?

Gaaaaack. Cause or symptom?!?

ahh, ok, I never ran any of that fancy stuff :mrgreen: used to keep my alk 9 -11 ish

Steve

Have you ever tested with that test kit before?

I remember once panicking over a so-called ammonia test reading when I was chasing weirdness but over time realized that the particular test kit I used never gave a reading under 0.1 or something.

Do you have a nitrite test kit that you trust? I would test for that rather than ammonia.

Honestly you shouldn't be having an ammonia spike unless something really big died in there. I don't think you have that.

I have used it yes. It's the one I use when I get new fish and need to monitor ammonia during the tank transfer protocol. I attempted a couple of iffy fish in the past few months that never made it out of QT, so I've used it recently. Expires in 2017. I also re-ran it using RO water and freshly mixed salt water. There's definitely ammonia in my system.

Since you only need to worry about ammonia during the tank transfer protocol, I haven't had a nitrite kit since I cycled this tank two years ago. I'll pick one up tomorrow.

I'm starting to develop an operating theory, but seeing as I never tested for ammonia until today I'll never really know for sure. It's very long so don't anyone feel the need to read it, but if someone wants to critique my thinking I'm happy to hear it.

In November I had a crazy cyano problem. To fix it I double-dosed the tank with chemi-clean (as in, repeated the treatment after 48 hours and a water change). I then immediately started dosing huge quantities of MB7. The effect on the system was pronounced - white bacterial slimes started growing like mad on the glass, my biopellet reactor turned in to a mulmy soup, and things generally just got really gross in ways they had never done before. It eventually lead to my biopellet reactor clogging up and failing, which is what I thought started all of this. I then took the reactor offline, cleaned it, and put it back online with a drastically enlarged effluent pipe and the same volume of pellets. Where I had been dosing something ridiculous like 70mL of MB7/day for the two weeks after the chemiclean treatment, I think I only did one or two doses of 10 mL after putting the reactor back together. I wasn't paying close enough attention to the tank or dates, but things started dying within a couple of days of that, followed closely a cyano outbreak of biblical proportions.

In March I shut down everything but the skimmer, started changing huge volumes of water every day, culminating in one massive 60% water change. I also re-dosed with chemiclean, which wiped out the cyano. Everything started to recover. At the end of March I put the reactor back online with a teeny tiny amount of pellets and dosed MB7 for a while. A month later, things fall apart again.

Contrary to what the makers of chemiclean would like people to believe, I'm pretty sure the active ingredient of that product is a form of erythromycin. They make a point of stating it contains no erythromycin succinate, which is a whole lot more specific than saying it contains no erythromycin, as there's 4 other kinds of erythromycin that I know of (estolate, stearate, gluceptate, and lactobionate according to wikipedia). Erythromycin works against gram positive bacteria, and all the "good" bacteria in a tank like nitrosomonas (the guys who munch on ammonia) are gram positive.

They probably get away with saying its safe because the kind they're using has less activity against the nitrifiers. The "true" nitrifiers metabolize and divide like a hundred times slower than cyano and heterotrophic bacteria, and erythromycin damages bacteria by making it hard for them to build cell walls, something that is particularly important during cell division. This should mean that a 48 hour treatment should be far less harmful to "true" nitrifiers than cyano and heterotrophs that divide every couple of hours, but it most certainly would have an effect on them.

In most people's tanks, I'm sure the effect is small enough to not cause any harm. But I double dosed. Then I started dosing with mad quantities of rapidly reproducing heterotrophs in an environment rich in organic carbon. And I have a 10 inch cow fish that eats more food every day than most people feed in a week. Since heterotrophs can also facultatively use ammonia as an energy source, I've read theories that suggest providing excess carbon during a cycle can lead to the rapidly reproducing heterotrophs outcompeting the nitrifiers for space and resources, creating a "false" cycle. When the heterotroph populations inevitably crash for whatever reason (run out of carbon or some other nutrient), there's nothing left to pick up the slack and ammonia levels start to fluctuate - long after the reefer has stopped measuring it. The theory is that this creates many of the phantom stability issues that plague new tanks.

It's very possible that this was all started by an OD of organic carbon when I modified my reactor, but it's also possible that the chemiclean treatment damaged my tank's capacity to process the massive amount of poop my fish make and I exacerbated/masked that by dosing huge volumes of MB7 in an organic carbon rich environment. It's possible that when the reactor clogged, they lost their food source and the population crashed, and my tank started to cycle and I just didn't know it. By the time I added the reactor back to the system there could have already been detectable levels of ammonia in my water, which, coupled with a sudden massive over-dose of organic carbon with hardly any bacterial dosing at all, caused a nasty positive feedback loop of corals death, causing more ammonia, causing more coral death.

I never measured it, so I can't say there was any ammonia in the water then for sure, but doing a series of enormous water changes fixed the problem. But then I dosed chemiclean AGAIN.

If any of the novel I just typed out is accurate, what I essentially had at the beginning of April was an unstable, half un-cycled 375 gallon tank packed to the gills with stressed SPS corals and a ridiculous bio-load. There were probably low levels of ammonia building up, but I was doing 20% water changes every 5 days or more at the beginning of April. I didn't, however, do a water change in the last two weeks of April, I just tested everything but ammonia. It wouldn't have taken much of a rise to push my already stressed corals back over the edge, creating another positive feedback loop.

I should also mention that during all of this, my blue-throat trigger developed a horrible case of pop-eye. It got a lot better after those big water changes, but last week it exploded again. It looks like his eyeball is actually going to explode. A couple of months ago I also started really noticing the gills of my copper-band butterfly. As in they're particularly red and engorged looking, but I thought that was normal and I had just had never noticed it before. Two weeks ago though, he developed a tumour under one of his gill flaps. My Richmond's wrasse has also been having some dermatological issues on one side. It looks like he's been trying to de-scale himself. I thought they were all unrelated, but put this all together and you get a picture of ammonia poisoning.

Again, all conjecture, but it's theoretically possible.

I've taken the pellets off the system, done a water change and dosed enough prime to get a zero reading on my ammonia test. I'm going to try and ride this out, and find a new home for the biggest ammonia contributor in my tank.

Well, your extreme actions, overdoses, etc, can't have been good for your tank. And if I remember correctly, you had your bio pellet reactor running offline for a while where it could have built up a lot of carbon from the pellets. Then the bacteria died, causing hydrogen sulphide. I believe you also discharged that into your tank, which then could have caused a die off in your live rock, which is still leaching out, and maybe causing your current issues.

So, a whole lot of things that could be causing your current problems. I think the old rule of not making drastic changes too quickly would apply here. That is especially important when using bio pellets or carbon dosing.

I used Chemiclean once (and followed instructions precisely) about 3 years, and it did the job well for me then. Have not needed it since, as I dose MB7.

And should test for nitrites too. If they also are high, and nitrates low, then you indeed are having a cycle. But with a 2 year running tank, and with all the die off now, would expect your nitrates to be high instead.

Vertex warns against taking bio pellets offline and rapid changes in water parameters, even for a short time, and the dangers of hydrogen sulphide. When you saw the excess clumping and mulm in your bio pellet reactor, you should have dismantled and cleaned it, before returning it to service.
http://www.jlaquatics.com/manuals/ve...structions.pdf

When I dosed the chemiclean the first time? I put the intake and effluent lines in a bucket of salt water outside the tank so the reactor never actually got dosed with chemiclean, is that what you mean?

Nope, the last time water from that unmodified reactor made it in to the tank was the day the effluent line clogged. It couldn't, the lines were totally clogged, and I was very careful about taking it out of the tank after. However by that point I think the damage was done cuz I'm stoooopid.

Well, I technically was following the instructions of both chemiclean and MB7. Chemiclean's instructions and FAQs say a second treatment after 48 hours and a water change is OK if the cyano problem is particularly pernicious, which mine was. I was also following the start-up dosing schedule for high nutrient systems (which based on the cyano problems I was having I thought I had) for my water volume printed on the back of the MB7 bottle. Now that I'm thinking about it I remember having done my math wrong for the maintenance dose. I thought it was 10 mL/day but you helped me sort it out as it was actually 5.4 or something. At that point I wasn't super awesome at dosing every day so I was either adding 5-6 mL/day, or more commonly 10 mL every few days if I'm remembering right.

I think you can follow product instructions and still get in to trouble. But as for the adage about not making changes to quickly, you are spot on. I was my own worst enemy. But to be fair, there's no way to dose chemiclean that isn't a sudden change. In three days you go from lots of cyano bacteria playing whatever role they have in your system, to high concentrations of antibiotics, to no more cyano. Using the product as instructed creates about as sudden a change as you can get.

Yah if I can get away to get a test kit today I will.

In theory that sounds good, but doesn't that put you in a d*mned if you do, d*mned if you don't situation? They warn against taking them offline or suddenly changing parameters, which I also did not want to do, but whether I had cleaned the reactor out at the first sign of mulmy grossness or after the effluent line had clogged, the effect would still have been a sudden removal of the pellets from the system and the collapse of whatever bacterial population the reactor was supporting. I know no H2S was being made prior to the line being clogged because I was opening the reactor every day or every other day to clean it's strainers, and after it failed I did dismantle it and clean it completely out. Once it started mulming up I can't see how I could have done anything that wouldn't have contravened Vertex's instructions.

Had to go back to you tank thread, and this is the post I am referring to. You said you took the reactor offline for 4 or 5 days and then you say you put it back online after that. You also added MB7 directly to the reactor at that time (and again wondered why the heck you would do that!!).

So, with it offline, the reactor (and bacteria) was obviously O2 deprived. And the effluent (carbon laden bacteria) had no where to go (supposed to go to the inlet of your skimmer). The build-up was probably the carbon laden bacteria, that was probably dying, too, with a lack of O2. You didn't mention hydrogen sulphide smell at this time, but could definitely have been present then, too.

The way bio pellets are supposed to work, is that bacteria forms on the pellets and they get digested and sloughed off with the nitrates, and need to be removed by your skimmer. If they make it into your tank, they will fuel cyano, if no other competing bacteria has been established (like MB7). That's why I don't understand at all the point of a recirculating bio pellet reactor. You want that digested carbon out of there as soon as possible, and into your skimmer.

Here are a few more links.
http://npbiopellets.dvh-import.com/i...-it-works.html

http://reefbuilders.com/2010/10/19/b...pellets-cheap/

http://www.vertexaquaristik.com/Port...lets%20FAQ.pdf

ooooh, I see. I think you misunderstood what I did. My reactor is designed to be external or internal. At that point its effluent line was tubing slightly wider than RO tubing, and in the inlet line was a bit larger than that. They're both flexible and a couple feet long.

When I say I took it "offline" I mean that I filled the big Salinity bucket I keep to store spent filter socks with salt water, put a small koralia in it pointed straight up, then put both the effluent and intake line from the reactor in that bucket while I was dosing with chemiclean. The reactor physically stayed in the sump and remained running, it just wasn't using water from the tank. The bucket was well circulated with tons of surface agitation so it shouldn't have gotten anoxic, but yes, for less than a week that it was like that all the organics that sloughed off would have built up in that closed system.

However the salinity bucket is like 7 gallons compared the the reactor's 2 or 3, and when I put it back 'online' with the tank I tossed all the water in the bucket, so 65% of whatever had built up got flushed. If that was enough to kill something, pellets aren't for me anyway.

Yes, and by offline, I do mean your bucket. That is a pretty tight loop, so water would still be O2 starved even with your koralia. And the presence of all that mulm/muck build-up could be trapped or dying carbon and nitrate laden bacteria, that isn't being flushed out into your skimmer.

And after you put it back online with your tank, the mulm/muck probably continued to build inside your reactor because your outlet was partially plugged.

I may have missed it in all your posts. But does your reactor effluent go directly to your skimmer input?

Despite all that, I am not saying either that was the direct cause of your current problems with your SPS dying. But it may have started the ball rolling, and caused other things to get out of whack. If your ammonia is high, though, sure does seem like a mini crash happening...

Again, I would do massive water changes. And keep that bio pellet reactor offline until everything stabilizes. Then you can start again with getting your nutrients under control, but this time, do things slowly and gradually, and watch your tank and corals closely to see how they are reacting.

If you look at the beginning of my tank journal, I started with a 100 ppm nitrate tank, with very high phosphates (after inheriting a 10 year running tank). It took me a year or more before I finally got everything under control. But has been running clean (zero nitrates and near zero phosphates) for a couple years now, and growing SPS like crazy.

I know your tank was looking great with all your SPS before, too. So with a bit of patience, I am sure you can do it again.