Hi there,
This question relates to my 38 Litre tank (an Aquaone AR380).
It usually has 2 dwarf gouramis, 6 neon tetras, 1 peppermint bristlenose and 1marble bristlenose along with a couple of live plants and a snail. It's been set up for about 5 months and continuously happy for about 3 months now (since I learned about nitrate, ammonia, cycling etc). In fact I successfully used the filter media from this tank to seed the filter during fishless cycling of my new, larger tank. I do a 30% water change every week.
So.......Since the last ten ?? days or so, I've been returning higher than normal readings on nitrate (between 10 and 20ppm). I started testing more regularly because one dwarf gourami was not "looking right" - a little less active than usual. I had thought it may be due to a small amount of bullying from the other gourami who is a bit bigger and chases him around a bit. But I have upped the water changes - I did a 40% change when I first noticed the problem with fish behaviour and nitrate (about 7 - 10 days ago) and have since done a 30% and last night another 25% change.
The not-quite-right-gourami is now looking very unwell: rarely moves/swims around unless chased, usually just lols about near the bottom or occasionaly at the top. He does not have any injuries and I've observed the bullying, it's a bit of chasing but no nipping or anything that looks too bad.
Now tonight I found the marble bristlenose dead (RIP
) when last night I was admiring him, how much he had grown and he appeared perfectly healthy etc etc.
Despite the 25% water change last night, my nitrate result tonight is again at 20ppm - last night it was only 10ppm. Ammonia is at zero and has remained this way throughout the whole crisis. I even tested my tapwater to make sure it wasn't high in nitrates but it is at 0 for ammonia and nitrate.
So I am wondering what on earth has gone wrong??????????
The ONLY thing I can think of is: I was advised by the local fish shop to never wash filter media (3 layers of fine and coarse sponge) in clean water but to occasionally give it a few quick squeezes in the dirty water as I'm doing a partial water change. Last week was the first time I have done this at all, otherwise I have left the filter untouched. This roughly coincides with my problem. Was this wrong? Do you think this is the cause of my problem? Or could it be something else altogether.
I have removed the healthy gourami tonight and put it in my other tank. The sick gourami and neons are still in the "sick" tank, I'm not sure what to do with them and what is going wrong?
Sorry this is so long, and I hoep my questions are not too dumb.
I hope you can help!
Thanks
Tiff