Cause of death: bullying, disease or cursed?

[Ben C.]

Parameters:

5.5 Gallon, No Heater, 7.4 pH, 0/0/10 ammonia/nitrite/nitrate, HOB filter, only Dwarf Emerald Rasboras and Ramshorn Snails

 

So I've got a bit of a stumper, and I'm starting to believe this tank is cursed, or something is very wrong. Over a year ago, I had a betta only in this tank with snails, and while he did fine for a while, he began to develop fin tears and rot, and I assumed it was because he was flaring at the snails constantly (and I mean constantly). So I gave him to a friend, and left the tank empty except for the snails for a month. Did several large water changes, let it stabilize, and then added some Neocaridina shrimp, only for them to die one by one, with seemingly no cause. So I left the tank empty again, let the snails multiply, and the plants grow. Then I added 9 Dwarf Emerald Rasboras after the same process. All was fine for a while, but now after about 4 months, 3 have randomly died overnight (on separate nights, spread out by about a month each). Only one was continually pale, but that one actually lasted the longest strangely enough. None showed any stopping in eating, or other behaviors such as odd swimming, lethargy, etc. Would just wake up to a dead fish.

I can occasionally see one (and not any specific one) flash, darting into the plant leaves and out. But nothing consistent. My only guesses at this point are:

1. Some resilient disease that has survived the long gaps of leaving the tank empty? All the Rasboras were quarantined after picking them up for 3 weeks, but there were no deaths in the QT tank.

2. Something is tainting the water - but all that contained in there are some unknown stones from the LFS, live plants, plus inert black sand from Petco. Snails have never slowed down, though. This tank does grow hair algae and cyano like crazy though. Despite when testing very low nitrates, and beginning a routine of 50% water changes and shorter light schedule, it still persists.

3. The largest Rasbora, which I've attached a picture of, is bullying the others to death. He's the only one that looks like that in the tank and has that size, so I'd assume the others are females, but I'm unsure. But he chases the other 5 tankmates any time he sees them, especially in the evenings around feeding.

 

I have no idea if any of this is related, but I'm at my wits end after the third death today. This tank has been nothing but grief for a whole year, while the rest of mine are thriving. Any help would be appreciated, thanks for reading my novel!

[xXInkedPhoenixX]

@benchilton how frustrating! I'm sorry I don't have anything to offer but: I had a 5 gallon tank that had a phantom disease even after I had taken it out and cleaned it, put in new substrate and started over. Ever since the last fish died and I dumped that tank I haven't had that issue since. 

[Fish Folk]

Hmm . . . have you ever stuck your hand in with a tiny abrasion to check for stray current? Sometimes a light can let off stray current and that can harm fish. What re your KH and GH measurements? Do you have enough air? Being without a heater, what is your room temperature? 

[Ben C.]

@xXInkedPhoenixX - I'm starting to think the same might be necessary for me. The stress is really making it not fun..

Edited April 25, 2021 by benchilton

[Ben C.]

@Fish Folk I have several knicks on my hands usually (who knew, chisels are sharp?) and haven't noticed anything, but I could make a sacrifical fresh cut to test. I don't have the exact numbers on KH and GH unfortunately, although I tested my tap a while back (which I use for water changes) and it was quite hard. Should I test again? As for air, I'm running a HOB on decently high flow, but I'm not running a stone. Room temperature sits around 72-75 daily.

[xXInkedPhoenixX]

I get it. That's where I was at. Finally decided when I couldn't figure it out despite trying pretty hard that it was time for it to go. It was a relief when I threw it in the can. Hopefully you do figure it out, from what I can see it looks like it's a nice tank. 

[Fish Folk]

2 minutes ago, benchilton said:

@Fish Folk I have several knicks on my hands usually (who knew, chisels are sharp?) and haven't noticed anything, but I could make a sacrifical fresh cut to test. I don't have the exact numbers on KH and GH unfortunately, although I tested my tap a while back (which I use for water changes) and it was quite hard. Should I test again? As for air, I'm running a HOB on decently high flow, but I'm not running a stone. Room temperature sits around 72-75 daily.

Well, don't cut yourself to test out a vague hypothesis! It occurred to me because just tonight I had a heater go bad, and the current was easy to feel.

I'd suggest adding an airstone. No promises anything will change.

What is the substrate?

[Ben C.]

@xXInkedPhoenixX thanks. It's not my favorite, but it's got a lot of plants. If I do scrap it, do you think I can salvage the plants? Maybe just a brief peroxide dip to prevent any spread?

[xXInkedPhoenixX]

I actually did save the plants and the moss ball from that tank. I didn't dip them either. just squeezed the moss ball out and put the plants in my new tank when it cycled. No issues since. 

...but a dip wouldn't hurt if you wanted to be extra careful of course

Edited April 25, 2021 by xXInkedPhoenixX
to clarify

[Ben C.]

@Fish Folk haha I kid, I'm sure I'll have a cut made organically sometime soon anyway...I'll try the airstone. The substrate is "Imagitarium Black Aquarium Sand". Whatever that is. With a little bit of EcoComplete I used underneath from an older aquarium initially.

[Ben C.]

@xXInkedPhoenixX great thanks!