# Polyurethane foam... toxic?



## bma57 (Sep 16, 2007)

Specs... 120 Gal, homemade wet/dry filter, established approx. 5 years. 12 Labs, 8 M. Estherae, 9 Acei, 3 OB Peacock hybrids, 1 BN Pleco, 1 High Fin Spotted Pleco, and 1 Syno.

Trying to improve my DIY wet/dry filter, I put a polyurethane foam pad from a fabric store in it as mechanical filter media. When I first put it in, it slowed flow to the point I was afraid I'd have an overflow. I figured it may do better after the air was all out of it, so I floated it in my sump for two days to let it get waterlogged. No problems so far.

Thursday night, I put it in the first stage of my filter and found that it seemed to be flowing fine.

Friday evening, I came home from work and turned on the tank light as usual and found multiple dead, one dying, and the rest in apparent distress, lethargic with clamped fins on the bottom. Suspecting the foam, I removed it immediately, put a bag of carbon in the sump, and did a 50% water change. I did another big WC this morning and removed and replaced all of my rocks (about 300 lbs. worth) to make sure I had all of the dead out, and all of the poo vacuumed up.

I'm sure my parameters should be good now, but I'm not going to check for a few hours. I just finished the cleaning and don't see a point to testing until the buffer has had a chance to circulate and everything stabilizes.

Last night, before the first WC, I tested... 80 degrees, 0 ammonia, 0 nitrite, between 40 & 60 nitrate which all seemed reasonably normal. I realize the nitrate was high, but I had a WC planned for today anyway. The only odd reading I got was pH at about 7.4. It's generally pretty stable at 8.0. Is there something in PU foam that will crash pH? Does PU foam put off toxic VOC's? Do I have something entirely unrelated going on that just coincidentally happened right after the foam was introduced?

Right now the water is super clean, I still have carbon in the sump, the lights are off, and I'm in "wait and see" mode. I'll do a full range of tests later in the afternoon, and keep checking for visible symptoms of disease. I lost 7 fish so far. Many of the survivors seem to be active and behaving normally, but a few still seem stressed, so I'm not sure whether or not this is over.

As always, your input is appreciated.


----------



## triscuit (May 6, 2005)

I can't find anything on the web about toxicity. But- I think you've answered that yourself.

Is that new carbon? If not, replace it with fresh (rinsed) carbon. Perform additional large water changes every day for a few days.

Also- nitrates above 10 ppm after a water change means your water is *not *"super clean." Not that I think the high nitrates were a cause of the deaths, but high nitrates means that other waste products are high, and will contribute to a fish getting sick more easily.

I like to see my nitrates still below 20ppm when I am ready to do another water change.


----------



## bma57 (Sep 16, 2007)

Thanks triscuit for the input. All in all, things are better, but the few that are still affected have a very odd symptom that I've never seen before. If anyone has experience with this, please share.

It almost seems like a neurological problem. One Estherae, one Lab, and one Acei all appear to be partially paralyzed. They hang on the bottom a lot, and when they do try to swim, it seems to take a lot of effort to move their tails. They swim vertically (head up) and appear to be doing much of the work with their pectoral fins. If they try to swim quickly, they pretty much lose control and twitch wildly. I have all three in a hospital tank now, and they were comparatively easy to net because they can't move normally. FWIW, the Acei is a pretty small fish, but the Estherae and Lab are some of the biggest, strongest fish in the tank.

If this sounds familiar, please let me know what it might be. Is it consistent with exposure to a toxin or does it sound more like a disease? Thanks.


----------

