Jump to content
momentarydiversion

New tank syndrome? What to test next?

Recommended Posts

My brother recently bought a small 25L tank and after scaping it and running the filter for a few days got a few small killifish to cycle it.

2 of them have since died (the first we put down to stress or just potentially bad luck) but the others seemed to be happy. However a second followed a few days later and now the third isn't looking very happy (luminent parts dulled, hiding up the back not moving a lot). I get the feeling this last one might be a lost cause, but before we try and add any more fish we obviously need to identify the issue so this doesn't continue. At this stage I don't think the tank is fully cycled, but would have thought 3 small (1cm tops) fish wouldn't have been overly taxing.

Details below

Problem:- Fish dying, sequentially a few days apart, seem fine until they lose colour, hide then eventually die (and we've not been able to find them yet)

Ph:- 7.4 - 7.2 when testing

Ammonia:- 0.25ppm

Nitrate:- about 5 (according to kit, could be higher)

Nitrite:- 10-20ppm

Gh:- Not tested

Kh:- Not tested

Size of tank:-30cm cube, 25L

Temperature °C:- 24

Been running for:- A week and a bit

Filtration:-Canister/Sump/Internal Filter/Sponge:- Hang on back Aqua clear 20

Fish in tank:- 3 (now 1) killifish

Plants in Tank:- Some val, some rotala and some lileopsis (sorry spelling) - Fertilizer put in once a week. DIY CO2 (Note: Maybe this is a problem?)

Feeding:- What food and How often: Micropellets, once a day. Visibly watching fish eat them, no more than a tiny pinch (5-10 granules)

Recent Medication Treatments:- None

Last water change:- 5 days ago

Water change every Day/Weekly/Monthly: - Weekly so far, but an extra water change when the nitrite started to creep up.

Any thoughts? Are these just the wrong fish (not enough in a school)? Should we test for more chemicals? Temp ok? Just too much bioload to start? Any other pollutants?

Link to comment
Share on other sites

c02 could be the issue here but it can also be compounding the amm nitrite and nitrate. the problem i tend to find with my 20l tank is that it takes next to no waste to start showing up in tests because with such a small environment it acheives a greater ppm because of the small literage. do you have a co2 meter?

Link to comment
Share on other sites

I'm thinking having looked into it a bit more that nitrite poisoning was probably the story.

I had (mistakenly) said to watch the ammonia and nitrates which were the issue, and I dont think we acted on nitrites enough.

So advice I'm getting is - don't use c02 until later, dont go for the killifish to start, and since we've got such high nitrites, just wait for the tank to cycle before thinking about a new fish?

Good plan?

Thanks everyone for your quick response

Link to comment
Share on other sites



×
×
  • Create New...