I have tons of bioballs in my fluval FX5 canister filter and i want to replace them with mechanical filtration foam blocks. Its only been running for about 2-3 weeks in my 29gal. Have they already developed significant enough bacteria populations to where i cant safely remove all of them at once and not risk an ammonia spike?

I'd think after only a couple ofd weeks you'd probably be fine, assuming you have plenty of LR in the tank to take up the slack.

I hope you're planning on cleaning the foam very regulary or it will turn into a biological filter pretty quickly.

How long has the tank been set up? What's in it in the way of live rock, specimens, fish, etc.? In 2-3 weeks, you aren't going to have too big of a bacterial colony established on the bio-media, but we could use more information about your system and your goals. And what Phurst said in that last sentence can't be stressed enough!

the tank has been set up since late september of 06'. its got about 30lbs of LR in there and currently the only inhabitants are my seahorse pair (H erectus). My main goal now is to use chemical filtration galore and get rid of the bioballs. Nautrally my next choice was to put the foam inserts in the filter for greater mechanical filtration. Right now i have chemi-pure, carbon, purigen and phos-guard in the canister filter, along with bioballs and some LR rubble.

You prolly have nothing to worry about, but I like to err on the side of caution when it comes to critters of the sea. Would it hurt anything to slowly pull them out other than it may be inconvenient to you?

i'm with Gwen here...pull half, then give it a week or two, then yank the rest.

and as mentioned, make sure you clean those sponges weekly.

i know you have some LR, but just to interject an idea...have you considered replacing the bioballs w/LR rubble?

and as mentioned, make sure you clean those sponges weekly.

i know you have some LR, but just to interject an idea...have you considered replacing the bioballs w/LR rubble?

I can do both of those. However i was not fully aware that having the foam blocks were as undesirable as they seem to be known as. Having already ordered them im not going to waste my 30 bucks. I will, however love the extra mechanical filtration and replacing the bioballs with LR rubble sounds like a great idea. Could i instead just use dry base rock? I have plenty of that lying around and i could hammer that up and use it in the canister if it would eventually turn live.

yes base rock is perfect and will turn live in a matter of time.

another trick is to take dead rock and aerate it in a bucket of SW and Fritzyme for 24 hours to give it a kick start.

foam material can be used with variable maintanence. the reason i say variable is because it depends on the bio-load &/ or the food your introducing. Take cyclopGeez for example, having filter material to trap the small particles is a given, where as if its a meaty fare feeding tank then its more than likely not going to collect in the filter. wether its bacterially alive or not, who cares, wash it in tank changeout water to stop populations dieing i say. wether you have pre filters, LRubble & chemical means within the housing the bacteria will still populate, so dont let the other scare you into thinking its bad, keeping it clean prevents extra load on the tank, thats all, which as we all know maintains better stability