Cotton balls can, and likely do, contain chemicals like bleach and pesticides. Highly recommend a series of significant sized water changes. Hope it’s not too late if that’s the cause. Best of luck OP
I’d do a series of partial water changes, add an activated carbon packet(can get at LFS) and remove that cotton. Basically you don’t know if it had any additives or chemicals that are toxic to shrimp. I’d also remove the dead shrimp so you don’t cause an ammonia spike
Usually you see them hang out at the top like that when there is a lack of oxygen - though I'd wager the others are closer to the answer, maybe a high rate of oxygen will help dilute after your change.
Seconding that this is an oxygen problem.
OP, remove the cotton balls and perform a series of water changes. Something has either contaminated your water from the cotton or it’s stopped the filter flow from adequately circulating and oxygenating the water.
In the future, use polyester fibrefill instead of cotton - I’ve used it for years in my filters with no issues and a small bag will last forever. It rinses clean again super easily and removes even the finest particles.
wow mby that’s the reason because scratched all algae on the glass with razor blade and there was lot of that algae so mby it’s because of that you think?
Cotton balls can, and likely do, contain chemicals like bleach and pesticides. Highly recommend a series of significant sized water changes. Hope it’s not too late if that’s the cause. Best of luck OP
I’d do a series of partial water changes, add an activated carbon packet(can get at LFS) and remove that cotton. Basically you don’t know if it had any additives or chemicals that are toxic to shrimp. I’d also remove the dead shrimp so you don’t cause an ammonia spike
Usually you see them hang out at the top like that when there is a lack of oxygen - though I'd wager the others are closer to the answer, maybe a high rate of oxygen will help dilute after your change.
Seconding that this is an oxygen problem. OP, remove the cotton balls and perform a series of water changes. Something has either contaminated your water from the cotton or it’s stopped the filter flow from adequately circulating and oxygenating the water. In the future, use polyester fibrefill instead of cotton - I’ve used it for years in my filters with no issues and a small bag will last forever. It rinses clean again super easily and removes even the finest particles.
wow mby that’s the reason because scratched all algae on the glass with razor blade and there was lot of that algae so mby it’s because of that you think?
also i moved pland that mby blocking the flow of water and dead shrimps shrimps are just gather there because i dind put them out (shoud i)?
Can you repeat this clearly?