I have a 90 litre tank. When I got the tank for a present, I followed all the advice on this forum about fishless cycling and managed to get everything set up correctly regarding nitrates, amonia, nitrites etc etc.
After checking everything was ok, I went to get some fish to get me started. I got 5 guppies and a swordtail. Initially, they did really well. However, after a couple of weeks, the guppies started getting fin rot and then died a feew days later. Treatments didn't seem to help at all.
5 weeks on, I now only have the swordtail and one guppy left. Both seem to be ok with no sign of fin rot.
My amionia, nitrate, and nitrite levels all remain ok. However, I live in a soft water area and my PH varies between 6.4 and 6.8.
Stupidly, despite following the advice regarding the fishless cycle etc, I seem to have totally ignored water hardness and PH levels when stocking.
I have two questions:
1. Is the PH level the likely reason for the guppy deaths?
2. With my PH levels as they are, can anyone offer advice on more suitable species for a 90 litre tank (I want a community tank).