Hi there everyone, I'm new here. So glad to find a forum that has discussions on these little critters, it seems to be rare, nice to finally find some other people who share enthusiasm for shrimp, it's not common over here in the UK (at least not in my area). I'm posting because I've had a bit of a tragedy recently and I'm hoping that someone will be able to help me prevent further problems.
My tank has been going for around 6 months now. It's a fully planted 28-gallon tank with dwarf rainbowfish, harlequin rasboras, baby zebra loaches and until recently some dwarf gourami and 10 amano shrimp. The ph is 8 (always high) ammonia and nitrite are at 0 and my nitrate is always less than 10. I do twice weekly water changes with conditioned tap water. The problem's I'm experiencing have been a developing saga so I will try to tell the whole story so the picture is complete.
The first sign of anything wrong was one of my amanos did not grow. All the shrimp were quite small when first put in the tank but they rapidly got bigger except for one. About 3 months ago, I spotted it darting around the tank, swimming really quickly and erratically and bumping into things. I separated it from the main tank but over the following days it's condition deteriorated to the point where it was just lying on the bottom of the tank, upside down, only occasionally moving a leg. I felt I had no choice but to euthanize.
The next thing to happen was a few weeks later one of my female gouramis got sick and died, followed quickly by the second female. There were no external signs of illness but they both had what can only be described as white stringy poo followed by a loss of appetite and listlessness. Having taken advice from my lfs at the time it was suspected that they fell foul of some kind of internal bacterial infection but all the other fish seemed fine so I was prepared to put it down to experience.
A couple of weeks later one of my rasboras "disappeared". I say disappeared because it was never found so has been presumed dead; in such a heavily planted tank, it is difficult to see much but an extensive search revealed nothing.
The latest fish death was my male gourami last week, I had been thinking he had been lucky to survive whatever had killed his lady friends but it was not to be. He exhibited the same signs as the others but also got some kind of fungal problem, probably cotton mouth. I was advised by my lfs to treat the tank to prevent the fungal infection spreading to the other inhabitants so started dosing with Protozin. The lfs said to be conservative with the dosing to avoid upsetting the filter bacteria and the loaches so I used only half of the recommended dose. Everything was fine for a few days until this weekend 2 of the shrimp started darting around the tank in the same way the small one had months earlier. As before, they were swimming very fast like they were on something, crashing into things and appearing distressed. Unfortunately, they didn't make it through to the morning.
As you can imagine I'm very confused. What once was a beautiful tank with happy fauna has become a constant worry. In addition, I now have a really bad stag horn algae problem. No matter how much I clean it, it keeps coming back. I'm not sure how many shrimp are left because as I said it is a very heavily planted tank, you never see them all together, but the ones I have spotted appear to be behaving normally, sifting through gravel and cleaning leaves etc.
Does anyone have any idea what could be wrong? I know many may think the medication had something to do with it but my lfs assured me that at such low doses it should have been safe for the shrimp. I am no longer medicating the tank and have changed some of the water twice to remove any residue. It doesn't account for all the problems though as I was only using it for a few days. Please, can anyone help me? What is killing my shrimp?