Major refugium issues.

[MizTanks]

I've been having cyno issues for quit some time in my fuge. Not a real biggy until now as I'm trying to maintain a decent pod population and my cheato won't grow.
I messed it up a long time ago by adding a heavy dose of salt trying to raise my salinity. Stupid move I know. Wound up killing everything off. Anyways....it hasn't been right since.
Today I took my intake pump off to clean it, fuge had no flow for a couple of hours at the most. Scraped some cyno off the fuge walls too. Well just now 2:30am I take a look see and all the cyno is dead, along with a bunch of amphipods and very inactive bristle worms. WTH?
Question is...do I tear it down, completely clean it out and add new sand and LR/cheato. Something just isn't right with it. I'm afraid it's going to start affecting my DT.

I do have a lil canister filter hooked up an running some carbon in the DT/ChemiPure elite, just in case.

[jimsflies]

Were your lights on when you looked at 2:00 am?

The reason I ask is that cyano tends to recede when the lights are off.

[MizTanks]

Only the fuge light was on. 18w cf.

[jimsflies]

I agree with Chris... bristleworms are pretty hardy. Cyano being gone is good... Cyano in the fuge isn't a major problem.

Gutting your fuge is taking a chance on upsetting the entire system.

[MizTanks]

Besides what all you are saying...Tearing it down sounds like to much work :)

[Jimbob]

A few questions which might also help or be useful for consideration:


What kind of substrate (if any) do you have in your fuge?
If you do have a substrate of some kind, how deep is it?
If you have a substrate in the fuge and it is >1/2" deep but <4+" deep, do you have any fuge critters such as snails or crabs, or ??? to help stir and clean that substrate bed naturally?
What is the flow through your fuge normally?
Do you regularly suck out the detritus and other accumulation of gunk from the non-substrate areas of the fuge?
How old and what kind of 18W CF bulb are you using to light your fuge?

[MizTanks]

3.6g HOB CPR Aquafuge. Mj400 106gph intake pump. 2" pink aragonite substrate. 18w cf 2 months old. No critters except for bristle worms/amphipods/copepods.

I've not touched it in any way as far as cleaning it out. But I really need to do it. It's just that's its so small that it would empty out in a minute via siphoning :(

[Jimbob]

3.6g HOB CPR Aquafuge. Mj400 106gph intake pump. 2" pink aragonite substrate. 18w cf 2 months old. No critters except for bristle worms/amphipods/copepods.

I've not touched it in any way as far as cleaning it out. But I really need to do it. It's just that's its so small that it would empty out in a minute via siphoning :(

A quick note on siphoning of small areas like this... a turkey baster is your friend, they can siphon a small area.

So... is it just the bulb that's two months old, or is it the entire HOB fuge that's only two months old? If the whole fuge is only two months old, I would propose to just leave it be, siphon out as much of the cyano as possible, and try to give it another month or two. If the fuge is older, and just the bulb is newer, then the below could be considered as you wish.

First would be to remove the 2" of pink aragonite substrate and either leave that area empty and have just the chaeto in there, or replace it with only 1/2" of substrate, or at least a 4" deep bed with some extra critters. Cyano thrive in two types of environments in particular:


Environments with a great deal of freely available PO4 / Phosphates, and
anoxic environments in where freel available nitrogen is very depleted


With the 2" substrate bed you have in there, it is very possible that the entire bed in the fuge has become an anoxic zone, especially with the low flow through the fuge. With a shallower bed of 1/2", it will not be anoxic, rather, it will always be aerobic and less conducive to the growth of cyanobacteria. Conversely, with a 4+" substrate bed in the fuge, the bottom several inches of the bed will become anoxic but there will be a better opportunity for the top 1/2" or so to maintain some aerobic activity, helping reduce a cyano-conducive environment. With the deeper bed, it would also be a good idea to add 2~4 nassarius snails or other sort of natural substrate sifter.

Other things to consider in general include:

PO4 levels... these can be brought down by feeding less or changing what you are feeding or skimming more heavily, slightly wetter than normal.

If that 18W CF bulb is a standard 10,000K bulb or similar, that's probably fine but if it is a generic cool white or warm white bulb from Home Depot, etc. the spectrum of the light probably isn't helping any.

The inlet compartment and outlet compartment of the fuge... detritus can build up in those areas. As detritus breaks down, it can become a source of PO4. It is a good idea to siphon those areas out every water change.

Hope some of this helps... at least maybe it can spark some thought for consideration.

[MizTanks]

The fuge itself is over a year old. The lamp is a Coralife 10k. Would removing the top 1/2" or 1" of the substrate in the fuge cause any issues? Don't want to be releasing anything nasty from underneath.

Part of me feels I should tear it up and start over with it. At least get rid of the substrate and add some new and less of it. My DT is pretty well established.

[MizTanks]

Ca=440-alk=9.1-mag=1340-no3=.0-no2=.0 and ammonia is .0
I'm not gonna mess with the fuge-to scared :) Just bummed out as my chaeto use to grow like crazy. But now it don't grow at all.

[Jimbob]

The fuge itself is over a year old. The lamp is a Coralife 10k. Would removing the top 1/2" or 1" of the substrate in the fuge cause any issues? Don't want to be releasing anything nasty from underneath.

Part of me feels I should tear it up and start over with it. At least get rid of the substrate and add some new and less of it. My DT is pretty well established.

I would not remove the top 1/2" to 1" of substrate from the fuge as that might make the problem worse.

If you plan on redoing the fuge and/or replacing a portion of the substrate in the fuge, I would recommend either completely emptying the fuge and replacing 100% of the substrate that is in it, -OR- replacing eithe left 1/2 or right 1/2 of the substrate.

Folks who use Miracle Mud or other similar substrates have to replace one half of the substrate each year... this isn't the top or bottom half though, but rather left or right half, etc.

[binford4000]

Small tank + Big changes = big mistake.

By opening up the substrate and removing 1/2" or an inch you would be releasing more nasties then you are now if you even are now..... what are your parameters?

This is good advice!! I would not mess with substrate either.with your No2 and No3 at zero the cheato will have a hard time surviving. Most times when it's that low cheato turns white and dies. Have you tried blacking out the fuge to kill it off ? I would go that route before messing with the DSB in my fuge.

[MizTanks]

Well actually the majority of the cyno has been killed off. During a WC and cleaning the intake pump the water level dropped so low in the fuge the cyno was exposed to air for a couple of hours.
However lights out did nothing in the past. It recedes at lights out but returns within an hour with lights on.

My main concern is pods being able to survive in this fuge as it is now? It's so small I know of nothing I could put into it to help with clean up.

[MizTanks]

Well I gotta do something because now my chaeto is dying. Breaking up into lil pieces and turning white. UGH! This lil fuge is just a mess and the cyno is starting up again. There are NO pods of any kind alive :( all that seeding it, what a waste. But the bristle worms are alive!

[MizTanks]

Is it possible that my heater in the fuge could cause problems without affecting the DT? The probe is in the DT. Of course the heater hasn't been on for a while though.
I'm trying to figure this out. Tonight I did see a couple of Amphipods in there, so this is good. But the chaeto looks like crap. Should I remove it and replace it with new? I need to figure out a way to do some light vacuuming in there without removing all the water and without all the loose crap reaching the DT. This really sucks :( My fuge use to be so nice.