Biological filtration for quarantine tanks

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AdamHorton

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Aug 12, 2009
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I have a 150G saltwater tank and I use live rock for biological filtration. During the entire process, I have kept two bags of the bio-max material from AC filters in one of the overflow cups so that it would grow beneficial bacteria on it. I did this so that if I needed to have a quarantine tank, I would not have to worry about that quarantine tank having to cycle.

Sounds good in theory, but every time I've tried this, the quarantine tank ends up cycling anyways, just like I'm putting in a blank bag of bio-max. Now I can do a fishless cycle on a quarantine tank in preparation for buying a new fish, but what if one of my fish gets sick? I'd rather not use LR from my tank since it would probably be ruined by the QT process. Am I doing something wrong here?
 
if you set it up and leave it with no source of ammonia it would make sense that it cycles again, the BB dies and has to be rebuilt because of starvation.

do you keep some source of ammonia going in the tank?
 
Yeah sorry I didn't say. The 150G tank has fish in it. I did a fishless cycle on that tank, with the bio-max material there and gradually added fish to where I am now.
 
Adam,

How big are the bags?
How large is the QT?
What filtration do you have in the QT?

In theory your method should work. You need to place the bags in an area of good flow, both in the DT (or sump) and in the QT.

I have a 30 gallon QT tank which uses a Penguin HOB filter with a bio-wheel. I keep the bio-wheel in my sump and add a new filter cartridge every time I need to use the QT tank. I still do a few 10% PWCs the first week to make sure there is no ammonia build up.

Have you tried doing your routine in the QT, adding a source of ammonia and seeing how long it takes to convert to nitrate?

I've done that test a couple of times and never saw an ammonia spike. So perhaps the bio-max is not as good as advertised, or you need more of them, or you need to place it in an area of greater flow.
 
The bags are from an AC20 filter and an AC30 filter. I've tried I've tried the AC20 bag on an AC20 filter in a 10G QT, and the AC30 bag on an AC30 filter in a 20G QT. I use AC for all of my freshwater tanks and I've never had any trouble.

Next chance I get I was planning on adding ammonia to the QT and seeing how it goes. That might be a couple of weeks, but I was hoping to add some fish at that time. I was just hoping to have a backup in place in case I need to do an emergency QT or something.
 
Well I got a chance to set up a QT. I took the bag of bio-max from an AC30 filter, which has been in my 150G SW setup for about a year now, and put it on a 20G QT tank with an AC30 filter. I added ammonia until it read 2 ppm and I've tested every day since then. That was a week ago. I've seen no decline in the ammonia reading and no change in nitrite or nitrate. Even when I was fishless cycling my 150G setup over a year ago with no biological "seeding" material I was making quick work of 2 ppm of ammonia after a week.

It's pretty clear that something isn't right here. I've never had any problems with AC filter media. My 150G setup is fine. It supports 19 fish, including 5 damsels and a tang, with no problems. I'm wondering what the next logical step is here to get my QT going. Should I take a piece of LR from my 150G setup (that's what I'm using as biological filtration) to try and seed the QT?
 
Just a guess here, but in your established tank you don't hit 2ppm of ammonia as the bioload is just not there all at once. Not all the fish are peeing all at once.

Obviously you can't put a fish into qt until the ammonia level is lowered. I wouldn't put rock into the qt as you won't put it back into your DT.

I don't think anything is wrong.
 
Are those the pad filter with carbon inside?
They might not have enough area for the amount of bacteria you need. I keep a biowheel in my sump and even with that I need to do a daily pwc in my qt for a week or so.
 
That's why I'm reluctant to put rock into the QT, because I basically won't get it back.

When I said I thought something was wrong, I meant that I expected to see at least some drop in ammonia by now. My only theory was that there was no bacteria to seed a new tank, but that relied on the bio-max material not being seeded properly from my 150G setup, which didn't make sense.

The bio-max is this type:
http://www.petworldshop.com/pictures/aquaclear-biomax-filter-insert.jpg
I'm using the bag for the 30-gallon filter.
 
Figures:

Tonight I take measurements and I see a small decrease in ammonia and a small increase in nitrite. Looks like the cycle is starting after all and I was being impatient. At least that problem is solved and I know what's going on.

That still leaves my original question though: why wouldn't that bio-max seed properly, and besides sacrificing some of my LR, what options do I have for an emergency quarantine?
 
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