Hi all, I've just joined the forum, though I have been lurking for quite some time. I'll try to keep my introduction brief, because I'm mainly here for some information mining, but I figure my fish-keeping background & tank set-up in pertinent so here we go;
Years ago when I was a kid my parents got me a 20g tank as a means of instilling a sense of responsibility, and I took care of it as well as you would expect your average pre-teen to, which is to say inconsistently at best. I housed a handful of different fish including gouramis and zebra danios until I hit college and priorities changed. That said, my understanding of water chemistry, the nitrogen cycle, and animal husbandry has grown since then.
Around January of last year my girlfriend found a 29g tank (for free) with accessories on a local FB trade/sell group, and as I had been keeping a 2.5g tank with a couple guppies for a year or 2 she though it'd be a good project/upgrade. I went to check out the tank and came to find out the owners were moving that day, did not plan to move the tank, and needed it gone ASAP. In the tank were 2-6" clown loaches the owners said were around 5 years old, along with about 30 (!) platies, 2 tiny plastic caves for hiding spots, and a Fluval 206 canister. I took the whole set up, along with a 20g, 10g, numerous filters, heaters, and other accessories, and got home feeling a bit overwhelmed.
I spent the next few months trying my hardest to make the 29g as suitable as it can be for 2 large loaches; frequent water changes, getting rid of as many platies as I could to lower bioload, and adding some "ciclid stones" and anacharis to provide more cover and hiding places. After some time letting the tank re-stabilize I also added 2 juvenile clowns to help the bigger fish feel more secure. Everyone was acting a bit more comfortable, the clowns fed enthusiastically, and the tank's other inhabitants were all looking good too.
A few weeks ago I came across a 55g tank that was pretty much free, and I decided to move the clowns to a bigger home to give them more leg room. I realize this is still not ideal, but I'm doing the best I can to get these fish in an appropriate environment, if nothing else it's better than where they started. The new tank came with it's own equipment and residents, the owner told me it had been running for about 7 years. I ran the tank for about a week before slowly transferring fish from the 29g every few days, eventually adding everyone to the 55g, and swapping the Fluval over to supplement the existing under gravel filter with dual Marineland MJ1200 powerheads. I re-homed more fish to get stocking closer to where it should be, and have been keeping the water at a steady pH 7.6, ammonia 0, nitrite 0, and battling to keep nitrAte around 20-40 with water changes until I can further lower stocking levels, or add more plants. These numbers are consistent with what I was seeing in the 29g prior to the switch.
Now for the cry for help and education; suddenly in the last week or so one of the adult loaches has stopped eating, developed pop-eye on one side, and has a bunch of scratches/abrasion on his head and face. Equally concerning, one of the juveniles has also stopped eating, become very pale, and lays listlessly on the tank bottom, unlike his vibrant, active young companion. What has changed? If it was just the adult I'd probably chalk it up to mechanical injury but 2/4 of the same species being sick while everyone else in the tank is acting normal has me a bit stumped.
I just wrote a novel for my first post, so much for being brief. Thanks to anyone who reads it, and especially if you can offer some advise. I know I've omitted some details so feel free to ask. I was planning to add pics for entertainment, but Photobucket is sucking at the moment, so it is what it is.
Updated with pics, maybe it'll be more interesting to read now...