tank crash

[gerald28]

hi bro my tank is a 2ft cube running on eheim canister 2215 ,prizm skimmer and an ios with carbon and coral chips ,it running well till recently i took out my cannister to replace the medium inside with i change to 2 kg of seachem matrix and 2 kg of biohome to create a better biological filter.About 3 days later my fishes start to die .Wat happen brothers ? is it i dusturb the filter but i never disturb my 3 inch sand bed! right now i could wish my remaining fishes are ok and start again

tks bros your comments are greatly appreciated

[Kelmen]

suggestion: run a water chk, especially on the ammonia.

I'm guessing the new replacement take time to grow the necessary bacteria, but during the course, not fast enough for your tank.

[ciaolong]

i wouldnt of change all the media at the same time maybe slowly do over a few weeks so the new bio media will have bateria on it

as kelmen said it takes times for the baterica and basicly now u have no where near the amount of baterica u need to cycle your ammonia that u usally have in your tank

[wil_lee76]

IMO i think u must let us know your water parameters first...rather than to conclude what causes the LS to die.

[hotlemond]

have a ammonia/nitrite test kit to analyze your case.

[Kelmen]

after some tests, and during the "recovering" period, suggest you run carbon for few days, then water change. To absorb leftover bad thingy (well, some good one too). The point is to get rid the bad one, with the simplest way.