水草情迷

I've done the following:
1. I put ÅK¬Ó«a into the tank
2. P10 was very dirty so I wash it and filled with fresh tap water. My tank is a 70L tank so I thought it won't affect much.
3. Bottom soil very dirty and lots of floating particles found. And the P10 seemed not functioning well, even after washed.
4. I put very little medicine in to the tank few days ago, but the amount was negligible.
Then all fishes struggled and felt sick. Stopped eating. I counted 15 out of 17 bb fishes died in one night. Now only the big fishes recovered.
I doubted the ÅK¬Ó«a contained some toxic chemical but I'm not sure. Can anyone help me to find the reason?

你係唔係瀘材都..洗埋呢.....?因為你咁既話會即刻破壞左成個缸既系統...
瀘材係唔洗換曬同埋洗架.......
另外...你係落左乜野藥呢?

I replaced the filter fabric
I washed the bio-foam
But I didn't wash the bio-ring
Was the procedure wrong?
If so, please recommend procedure.
I used AZOO Pathogen Preventer.

e...應該冇問題架播...
會唔會係你加鐵皇冠既時候太大動作呢?(即係攪到沙塵滾滾....^.^)

Poisonous ÅK¬Ó«a............
I still keeping it, may try with a silver needle.....to check poison