Backyard Aquaponics
A place to discuss aquaponics

http://www.ponddoc.com/koihospital/Diag ... Dropsy.htm

cheers

What you are describing is not dropsy nor does it sound like swim bladder. When fish end up lying on their side it means they are about had it hence death next step.I would suggest taking one of the weak but live fish to a local trusted aquarium store and get them to give the fish a thorough examination,for yourself maybe lift open a gill plate of one of the crook fish and check the gills see if they are pink or white(due to infection).
just re read your post losing 10 fish over 3 mnths is not a chronic disease outbreak problem as you usually lose larger numbers quickly. If the ones that are dying are the runts then it may just be the quality of those fish
cheers
Byron

I would stop feeding for a few weeks and add some salt to the tank.

When you do start feeding, try getting a cheap $2 pepper grinder and crushing the pellets from that to feed then.

Is the system new?
You could still be cycling. If you are you want to reduce feeding anyway

Thanks all,
SolTun, nice link. Not dropsy as they're not pineconey nor bloodshot (maybe a bit bloated).

Fishman, Thanks. the gills should be pink if healthy yeah? I wouldn't have called it an epidemic until now, as I had 2 more floaters today, and 2 that look like they will be tomorrow Deaths are accelerating. Haven't had this many die since my great freeze in January. It's weird, all of the dead ones are in the upper FT that the GBs drain into. The lower FT that the upper tank drains into (basically an ST but has fish in it too) hasn't had any deaths (I probably just jinxed it though...). It could be one batch (stocked fish in 4-5 purchases) and/or the runts as you say.

Werdna, yeah I'll stop feeding and do a salt. Good time for it as transitioning the greenhouse over to summer mode. Winter plants are completely dropping off and summer plants just kicking into gear. I wouldn't call it a new system per se, had fish for 3 months last fall before they froze in early January. Started restocking current fish by late February and been running pretty well since then (minus my climate playing havoc with the plants).

I've had another death, and one more looks like he's on the way out.

i need to solve this or i'll lose them all at this rate. the only other thing i can think of is it's something to do with the galv mesh i have over the top of my tank to keep out birds and kids.

the deaths always start after it rains, maybe it's sinsitivity to the zinc coating.

the only thin left in there now is the mint floating. there's no known issues with mint is there?