25g Mid-Week Detritus Export Video
 

The subject came up in other threads about how much detritus can be removed from a BB tank. Here's a video made this morning of my 25g Mid-Week Detritus Export regime. Please note, there aren't any fish or inverts in this tank - except for the inverts that hitch hiked in on the LR. Seeing how dirty the water gets mid-week and during weekly maintenance, I'm so glad to have a BB tank :)

Hey Bev do you do house calls :mrgreen:

I have a 60 gallon bare bottom tank with two fish... my foxface makes a big mess. I usually stick a filtersock in the sump which filters anything that goes down the overflow, then use a tube to target siphon detris out and into the sock. Then I remove the sock and clean it out. Works good, but it would be nice to find an easier way.

Why not just use a clean up crew?

I use the same technique but let my two skimmers do the dirty work.
That leads to more frequent skimmer cup cleaning but hey i need to do it anyway.
To make this work a lot of internal water flow is a must to keep particles suspended.
i doubt that any clean up crew will go for the dirt that has no nutritional value.
Filter feeders and cucumbers will, to a degree but they also generate waste so it a vicious circle the more life we put inside the more waste it will generate even is we call it "Clean up crew"

Or have the powerheads aimed to suspend the detrius in the water column and get a hob skimmer or your hob filter to remove them ?

You beat me too it !

Beverly is using HOB

LOL, Rich!

Marko, besides a few corals that don't get fed, are stomatella snails (lots now, after the spawning event a few months ago), pods and a few small brittle stars - which would all qualify as a clean up crew, wouldn't you say? Man, they leave a mess! I get about this much crud when I do weekly maintanance, too.

Don't you all wonder what's accumulating in your sandbeds?!

Hey Bev,

Do you rinse in the bucket because you want to use only tank or RO water. I never really went that far when rinsing sponges, but maybe I should have. Would you do the same for socks?

And second thought, maybe you just did it for our benefit to see how dirty they are. Sorry blonde moment

I use tank water in the bucket to rinse the foams to preserve the nitrfying bacteria in the foams. RO or tapwater would kill the bacteria. I don't use socks, but would probably use the same method for rinsing. I've read that some people have a bunch of socks that they rotate daily and wash, which might be better than simply rinsing them.

I have over 200 hermit crabs. Sand and rocks are nice and clean looking.

To Marko and anyone else who'd like to do an experiment :biggrin: :

Could you please take a cup or so of sand from your sandbed (or sump), preferably near or under your rock, put it in a jar with some tankwater and shake it? Post photos of what the jar and your sandbed looks like during this process. I'm guessing the jar water will turn a shade of brown, but that's only a guess.

Looking forward to seeing a whole whack of photos!

I only have an inch of sand bed. But why does it even matter? There's so many successful reef tanks with sand.

My only concern is that it looks clean

You are correct it only looks clean.
I always end up replacing or getting rid of the sand because it gets full of detritus. No meter how much i like the sand if i don't get rid of it in a year or so it always get foul. I never put more then an inch also, And i have about 100x+ water flow in my display tank without counting a return pump flow.

I've been following this discussion, as I am in the process of redoing my upstairs display tank, and need to decide whether to go BB or a thin layer of sand.

Currently, I have about 3 inches coarse sand, and no question it collects a lot of detritus. I vacuum the sand bed regularly, but much of it is inaccessible under the rock. I have high nitrates and phosphates (although lowered recently with bio pellets), and I think this is the main reason.

However, I do like the look of the sand, so at the moment am leaning towards having a thin layer, just enough to cover the bottom, and see how that works.

Another consideration, might be that the sand contributes to the nitrogen cycle, just like the live rock, and eliminating that may reduce the capacity of my tank to manage the bio load with fish and feeding.

When I upgraded from the 10g to the 25g before Christmas 2011, it was on my mind to put a thin layer (under 1") of sandbed at a later date. However, with all the detritus I'm pulling out weekly (with no fish to feed and no coral feeding), I've decided to keep the 25g BB. With the BB, I can see that a lot of detritus accumulates under the rock. Turkey basting gets that crud out from under there where it can be either siphoned out or blasted into the water column for the foams in my HOB to catch and to later be cleaned.

Yes, I looked at your video. But wouldn't a sand bed, with its beneficial bacteria, consume some of that detritus through the nitrogen cycle and go out as skimmate (after the the bio pellets do their job)?

I can see why a deeper sand bed can accumulate N03 and P04, but a thinner one, with good water flow, should help to consume detritus instead. Or is that just wishful thinking on my part?

I don't know what you mean by consume. The sandbed will have nitrifying bacteria, but you will still be left with nitrate and phosphate as a result. At least, this is the way I understand the process.

If you remove the detritus, you remove the resulting nitrate and phosphate - unless you have chemicals that do that for you. I'm not up on biopellets or those things, but I do have elbow grease and don't mind getting my hands wet :)

Video I shot this morning Detritus the Day After Mid-Week Detritus Export. As you will see, there is still detritus in the tank. It only really clears up after I siphon it out during a 20% water change - only to begin reappearing again that night.

By consume, I mean "eaten" by the nitrogen cycle. In other words, you would have less visible detritus as in your video. Instead it would be trapped and consumed by the bacteria in the sand. I can see there would be a limit as to how much the sand can consume, and detritus will become visible if there is too much.

Before I was using bio pellets, my tank was a real mess with detritus and algae covering my live rock and sand. My nitrates went as high as 100 ppm (now less than 20). I had to frequently scrub my rock with a tooth brush, just to try and release more detritus into the water where the flow could move it to my sump with the filter sock and skimmer.

But after I dosed with MB7 and bio pellets, the visible detritus all but disappeared, and I stopped scrubbing my live rock. I still vacuumed the sand bed. But gradually my rocks became clean and shiny with coralline, and the nuisance algae all disappeared. So that's why I think that beneficial bacteria (which need a surface) have a lot to do with a clean tank.

I can only guess that the MB7 and bio pellets are doing what they are supposed to do. Is the water in your pail dirty after vacuuming your sand? How dirty your water is indicates how much detritus your sandbed still accumulates.

I'm wondering if anyone has taken the time to do the sand and tankwater in a jar experiment I suggested earlier in this thread :)

Yes, the water from the sand is still dirty after vacuuming, but a lot less now. I think the MB7 is what probably makes the biggest visible difference in my tank. The bio pellets just take out the nitrates.

You should try it in your nano (without the bio pellets) just to see what it does.

Oh, I don't use bio pellets and don't intend to use them. And, no sandbed to put in the jar :wink:

Just wondering if anyone thought of doing the experiment for their own information and to share with the rest of us :)

last time when i used bio pellets i lost about $450 worth of my best SPS.
Plus the $$$ lost to buying pellets and equipment.
Will stick to overskimming for now.

I didn't want to turn this thread into a discussion on the merits of bio pellets. Some have been successful using them and some have not. There are many potential reasons for this, and it has been extensively discussed elsewhere.

I became interested in this thread to try and gain a better understanding on the role of a thin sand bed and its relationship to detritus and ability to increase a tank's bio load capacity while maintaining low nitrates and phosphates. Beverly highlighted how much detritus is generated even in a BB tank. But what I am not sure of is whether this detritus is reduced with a thin sand bed because of the beneficial bacteria that would reside there and consume it.

Also, would be interested if just the use of MB7 (without bio pellets) would reduce detritus. I know in my tank, detritus (and algae) was dramatically decreased (along with the reduction of N03 and P04) after I started using it with my bio pellets. But have never tried MB7 without the bio pellets. I might try that later after I reset my upstairs display tank.

Oh Beverly, you ain't seen nothin'! Even with only 2 fish in a 50G, restricted feeding and aggressive Vodka/MB7 dosing it is still terrifying when I do detritus export. Have you ever seen that scene in Raiders of the Lost Ark where they open the ark and that dude's face melts off? It's like that but with less face-melting.

Actually, ever since going the Vodka/MB7 route it's been worse. Most people are surprised by this but they're missing an important part of the bacterial cycle. Bacteria are a living, growing things. They consume nitrates, phosphates, and carbon to produce biomass (ie. grow!); they grow, reproduce and die. If you carbon dose you turbo charge this process. A lot of what we call "detritus" in our tanks is actually bacteria (unless you have one of those "poop factory" fish, it which case it's all crap). This keeps your water clean but if you don't clean your sand bed (or any other porous material in your tank for that matter) regularly, bacteria builds up (along with all of their dead soldiers). If you don't remove the dead bacteria from time to time, they just begin to decay and release the nutrients back into the water.

So yes, having BB does reduce this because there is no sand for bacteria to grow in and it's very easier to blast it out of the tank. But then again, BB is missing an important aspect of the bacterial filtration: a high surface area media on which to grow (very little of the bacteria in our systems are suspended in the water column). I agree that BB is way easier to maintain and have been tempted to go that route before but I, personally, am still attached my bacteria growing substrate. I have been wondering though what is the minimum amount of substrate I can get away with?

No, it doesn't really reduce detritus because detritus is mostly bacteria as per above. Sure, it will break down some of the solid matter but the matter that gets broken down doesn't magically disappear, it gets turned into more bacteria! (Newton says "Matter can neither be created nor destroyed". Mass balance baby!)

The above is correct the more surface area provided the more bacteria will grow.
The way I got it set up is I use a " acrylic box in the sump" that my overflow is being emptied to so there is a lot of flow in the small container. And that is where I have my send about 1.5" inch. Not as mach as in the tank bottom abviously but better then nothing.
So two things achieved: One no detritus in the display tank two surface area is provided for bacteria to grow