Search the Community

So I have a 20 gallon long that’s been running since November 2020. I originally got a group of 6 celestial Pearl danios that started in my 10 gallon tank that I moved to my 20. I had 4 males and 2 females. I had one successful spawn right before I went out of town so I lost all the fry while I was gone. Since then I’ve added a blue stiphodon goby (which disappeared, might’ve accidentally been taken out with some plant trimmings?) 7 Habrosus corydoras (lost one but I think something was wrong with its mouth, it never seemed to get bigger and was always skinny, and it’s mouth looked weird). Then I added 4 gertrudae rainbow fish (2 males 2 females) and have had 4 different super red bristlenose plecos (1 re homed when I found out my female was really a male, then one of my two remaining males died, so now it’s a new female and the original female that ended up being male). I also have a male apisto hongsloi that I added at some point as well. I randomly lost a male CPD a few months ago, it seemingly overnight had become almost rainbow 🌈 shaped and it’s mouth was moving really rapidly, like it was breathing heavily. No other signs. I tried isolating it and it died. The cory when it died I think it just wasn’t able to eat due to a mouth deformity. The male bristlenose died right after a water change, which I had dechlorinated and was slightly cooler than the water in the tank, so no idea what happened there. This has been over the course of the last few months. About a week and a half ago I added 3 new CPDs that were juveniles that had just recently moved up to the floor (my local fish store does a lot of in store breeding) and today during my water change I found one dead, it had probably died maybe 2 days ago, some decay but not enough where I didn’t know what it was and I’d seen all 3 of the new ones recently. This morning prior to the water change I also noticed 1 of my male gertrudaes was staying towards the top right at the surface, whereas the other three were swimming around the mid and top level like normal. I also noticed another of the male CPDs was doing the same as the one previously did before it died. before my water change I tested the water, there was 0 ppl nitrite, 5 ppm nitrate, 300+ on general hardness (according to CoOp test strip) and 40 kh on the CoOp test strip, with a pH of ~7.2. My temp was probably around 79 since my heater was off but it didn’t feel extremely warm. I did my water change, took out about ~25% then dechlorinated with the Fritz that the CoOp sells with the pump head, I did 2 pumps then filled the tank from my tap then added another pump just for good measure. a few hours after the water change and the CPD and gertrudae were still acting funny so I put them in a Lee’s container on the tank with an air stone, half a tbs of salt and 10 drops of Prazi pro, and within an hour the CPD died. of my original 6 CPDs only 1 female and 2 males are left, and only 2 of the 3 new ones remain. Filtration wise I have an aqueon 10 HOB, a medium sized CoOp sponge filter, and I just upgraded my other HOB to the tidal 55, I kept all the old media and added seed. That change was done this past Friday. The flow is as low as it can go but the fish don’t seem to mind, I’ve yet to see anyone struggling in the flow. I tested using the API Kh kit snd my Kh was ~4 after the water change (which is what I normally run) and ammonia was .5 (but I’d also Just done a water change) so I threw more seed in. im really at my wits end as to what is going on, why I keep having random fish deaths when everything else looks healthy. my LFS keeps new fish under observation at least a week, treats when necessary, and I keep an eye on the fish for several weeks before I take them home (I work at my LFS). I do weekly water changes, I test my water frequently, but I’m really at my wits end as to what’s going on in my tank. Below are some pictures of the gertrudae that I’ve isolated, the freshly dead CPD, and then the tank itself and some of the fish in it. Any advice or ideas would be greatly appreciated, my best idea rn is possible gill flukes? Since I see some red in the gills, but I don’t reallly know much about them yet (I’ll talk to our aquatic vet staff at my LFS tho when I work tomorrow).

I was looking into getting dwarf emerald rasboras, but never see them anywhere around here. I'm wondering if they are sensitive or can't handle our hard water/high ph in the area. It comes out of the tap at 8.4. Does anyone have experience with them?