I have a standard 6 foot 125 gallon planted aquarium, and have recently discovered that I have 2 dead fish and a pretty bad ich breakout after returning from a 5 day vacation last night. It may also be worth mentioning that the tank has been running for about 3 months now, and I've been fighting a brown algae problem for the past few weeks as well (although the water parameters all still looked excellent: Ammonia: 0, Nitrite: 0, Nitrates: <20). Other than that, everything seemed fine before a left for vacation last week. There are about a dozen various plants in the tank along with three smaller moss balls and lots of driftwood. I'm running two emperor 400 filters and 135 watts of flourescent lighting (75 watts at 6500k, and 60 watts at 6700k) 9 hours a day. I feed a combination of pellets, freeze dried bloodworms, flake, and an occasional algae wafer twice a day.
Stocking wise, here's a list:
1 female crowntail betta (RIP, I know this is an odd choice for a 125 but she actually did great in there with the other fish since she was 2.5" herself. That said, I don't believe I'll be replacing her.)
1 rubber lip pleco (RIP)
3 pictus (currently 3", LFS told me they were the 6" variety)
1 clown pleco (currently 2")
6 Bala sharks (currently 2-3", I know that these guys get big but have never seemed too aggressive to me)
weather loach (currently 3")
6 denison barbs (currently 2-3")
3 rosy barbs (2", will be adding 3 more once I get my issues resolved)
3 congo tetras (2", will be adding 3 more once I get my issues resolved)
2 kribs (3.5" Male, 2" Female)
Pictus Cats and Clown Pleco were very lethargic and covered with ich. I had to remove the two partially eaten dead fish, and immediately did a 50% water change. Ammonia looked to be less than 0.25 ppm when I measured after the water change. I added prime and aquarium salt with the 50% water change (Ammonia was 0.25 ppm, Nitrite: 0, Nitrate: 20). I use Seachem Ph neutralizer since I have tap water, so I don't regularly test Ph. I've never used the aquarium salt before, but figured it couldn't hurt in this situation. I opted to not treat the ich with medication, but instead gradually increased the temp of my tank from its normal 75 degress to the mid 80s. It was at 82 degrees this morning before I left for work, and the pictus cats and pleco were much less lethargic. The pleco was even eating an algae wafer. However, my male Krib looked very stressed and was breathing heavy. I went ahead and set the heaters to rise to 84 degrees, and left for work.
I hope my male Krib will hang in there, since our little Krib pair are our favorites along with our weather loach (the only ones with names... of the remaining fish). My thinking is that one of the fish died soon after we left and mucked the tank up pretty good over the next few days before we got back. I just never would've expected to have ich, since I've never had problems with it before and there were no signs of it before we left for Vacation. The rubber lip pleco was one of the newer fish, and I was only able to watch him for a couple weeks before we left. Maybe he was carrying it, and when he died it spread rapidly due to the ammonia spike as well. I'm really at a loss for how exactly it happened, but I guess all that matters at this point is getting the tank healthy again.
So my plan of action as of right now is:
-More regular (daily?) water changes with Prime, Ph Neutralizer and Aquarium salt
-Add more airstones to the tank
-Maintain a temp between 84-86 for an extended period (2 weeks?)