Grrr. My biopellet reactor died

[asylumdown]

Not in the mechanical sense, the biological sense.

I've got a recirculating biopellet reactor from Reef Dyanmics. I've always been a little annoyed at some of what I would call its design 'flaws', but I've always been able to manage them. Specifically, because it's recirculating, there's two grilled intakes inside the body of the reactor, one is the intake for the recirculating closed loop, and the other is the intake for the outlet to the reactor. There's one pump, so you control how much water gets recirculated, and how much water leaves the reactor via a series of valves.

The problem I had from day one was that the intake for the recriculating closed loop, which is lower in the reactor body, was constantly getting clogged up with biopellets, shutting down the tumble. I'd have to shut it down, open it up and clean the grill off with a toothbrush at least once a week. No tumbling's not so bad, as all that happens is the pellets form clump, but it's annoying.

Now, since I treated for cyano a while back, I started dosing MB7. I'm not sure if my BP reactor simply wasn't working for years before, or if my tank had more nutrients than I thought, but that kicked bacterial production in the reactor in to serious over drive. So much so that I barely dose MB7 anymore because it's such a PITA to deal with. The outlet for this particular reactor right is at the top, with a john guest fitting that connects a long hose (only slightly larger diameter than RO tubing) so that you can direct the outlet to the protein skimmer.

Problem #1 - that stupid outlet hose isn't nearly wide enough to deal with copious production of bacterial mulm. Even with the valve open full bore, water doesn't travel down that tube at a high enough velocity to prevent serious biofilms from forming inside it. In the first 2 weeks of dosing MB7 at the concentrated 'start up' dose, the outlet tube clogged completely with what looked like congealed white snot. It's too narrow and long to get a pipe cleaner down it, so I had to fill it up with bleach and let it soak to clean it out properly. I've been having to disconnect the hose and blow hard on it every few days since to keep water moving through it efficiently.

Problem #2 - that stupid grill! Again the grill on the outlet line has slats so narrow, that any piece of mulm thicker than a couple mm gets stuck on it. I've been insanely busy the past 5 days, so I wasn't checking the hose every day like I usually do, but tonight I pulled the outlet hose out of the water and not a single drop was coming out. Since it's recirculating, the pellets inside were still tumbling away, but no water was actually entering or exiting the reactor.

Anyway, this clog obviously happened a few days ago, because when I opened the reactor, my entire house -upstairs and down - very rapidly filled up with the most noxious, gag inducing smell I've ever experienced. Imagine 2 dozen rotten eggs, that had been sitting in the sun for weeks, suddenly being smashed on your floor all at once. My roommate came downstairs in a panic because she thought there was a gas leak.

Cue two hours of emptying and scrubbing out the entire thing when I had wanted to be in bed. I probably removed a pound of rotting bacterial mulm and biofilm from inside the reactor.

All I have to say is thank goodness rotting things smell so badly, or that it didn't unclog itself before I took a look at it. I have one of the biggest versions of this reactor that they make, so I think it holds around 2 gallons of water. I can't imagine what would have happened if that much putrified water and rotting organic matter had made it back in to my system all at once. Not sure if the pellets are worth saving or not, but I gave them all a thorough rinse anyway as unwashed I couldn't even put them in the garbage they stank so badly.

Moral of the story: I love the idea of a recirculating BP reactor, since it lets you set the tumble rate independent of the flow through rate, but I'm seriously hoping there's been some design enhancements to them over the last two years. That shouldn't have been possible.

[FishyFishy!]

Sorry to hear that brew. But if you're thinking of continuing the use of BP, I would suggest you chuck the obviously flawed reactor and go for a better design. Sounds like nothing but problems for you.

[Reef Pilot]

Never could get why the circulating, when these reactors first came out. Bought my Vertex UF20 several years ago and has been totally hassle free ever since. I have it T'ed off my return pump and it has a ball valve on the input that allows easy control of the tumbling. Only maintenance was topping up pellets every few months. I have had as much as 1000 ml bio pellets running in it. Never requires cleaning or maintenance. But with zero nitrates for so long now, my bio pellet reduction has drastically slowed, so haven't touched mine now since Nov/2012, and still has about 1/2 cup tumbling in the bottom.

[asylumdown]

Originally Posted by Reef Pilot

Never could get why the circulating, when these reactors first came out. Bought my Vertex UF20 several years ago and has been totally hassle free ever since. I have it T'ed off my return pump and it has a ball valve on the input that allows easy control of the tumbling. Only maintenance was topping up pellets every few months. I have had as much as 1000 ml bio pellets running in it. Never requires cleaning or maintenance. But with zero nitrates for so long now, my bio pellet reduction has drastically slowed, so haven't touched mine now since Nov/2012, and still has about 1/2 cup tumbling in the bottom.

If I can't get this thing modified to work the way I want, that's exactly what I'm going to have to do, though I've no way to T it off my return pump so It would mean buying another pump. I'm trying to spend as little money fixing this as possible first.

[Delphinus]

Sorry to hear. I'm with others on this thread, that outlet sounds too small.

To be honest, I find the whole trend of "recirculating this or that" (skimmers, reactors, etc.) to be a little bit of needless overcomplication. The fact that these units sit in sumps means that water is recirculated even on one-pass designs anyhow. Generally speaking, KISS principle is the way to go.

[asylumdown]

yah the only logic behind it is the setting tumbler ate independent of flow, but these problems with mulm building up inside the reactor (let alone clogging parts) just doesn't seem to happen with one pass reactors, as the water moves at such a clip it's evacuated as soon as it's produced.

I wouldn't buy one again, but it was 4 or 5 hundred bucks and I don't want to replace it it so I'm going to try and work with what I have. I'm 99% certain I can address it's most serious design flaws.

Tony, you know anyone in Calgary that's got a drill press? I will even supply my own drill bit...

[Stones]

I assume this is the reactor that you are talking about? This is obviously a design flaw having such a small outlet for the effluent. Most reactors come with 1/2" or 3/4" outlets and even those can fairly rapidly narrow due to build up of bacterial mulm.

If you have access to some NPT taps, I'd remove the factory john guest valve on the top of the reactor and drill/tap a new hole large enough for at least a 1/2" threaded PVC elbow. Then you can add a 1/2" ball valve to control the effluent rate and by increasing the diameter of the outgoing plumbing, you should no longer have to worry about plugging off solid any more.

My biopellet reactor went anoxic and smelled the same way after I forgot to turn the flow back on after a water change. I removed all the pellets and let them soak in RO/DI until the sulphur smell had dissipated. All of the bacteria obviously had died but the pellets started working after a few good does of MB7.

By the looks of it, there isn't much you can do to help alleviate the clogging screen for the recirculation part of the reactor. My only suggestion would be to cut a circular piece of needlepoint plastic (available at places like Michaels) and wedge it in the reactor just below the intake screen to help prevent pellets from circulating that high up in the reactor.

[asylumdown]

Originally Posted by Stones

I assume this is the reactor that you are talking about? This is obviously a design flaw having such a small outlet for the effluent. Most reactors come with 1/2" or 3/4" outlets and even those can fairly rapidly narrow due to build up of bacterial mulm.

If you have access to some NPT taps, I'd remove the factory john guest valve on the top of the reactor and drill/tap a new hole large enough for at least a 1/2" threaded PVC elbow. Then you can add a 1/2" ball valve to control the effluent rate and by increasing the diameter of the outgoing plumbing, you should no longer have to worry about plugging off solid any more.

My biopellet reactor went anoxic and smelled the same way after I forgot to turn the flow back on after a water change. I removed all the pellets and let them soak in RO/DI until the sulphur smell had dissipated. All of the bacteria obviously had died but the pellets started working after a few good does of MB7.

By the looks of it, there isn't much you can do to help alleviate the clogging screen for the recirculation part of the reactor. My only suggestion would be to cut a circular piece of needlepoint plastic (available at places like Michaels) and wedge it in the reactor just below the intake screen to help prevent pellets from circulating that high up in the reactor.

That's exactly the one! I stopped off at Concept today and Denny got me set up with everything I'll need to modify the effluent manifold to 3/4" piping with a ball valve. However, I was an idiot to think I could drill out the hole needed for the new bulkhead using a hand held drill. I'm going to see if I can get access to a drill press in the next couple of days here, I'm hoping my dad has one.