These are the mediums in canister filter

Just replace a new canister filter few days ago, all are back to normal. At the same time, replace some mediums. Yes of course, the beneficial bacterial is a must in the canister filter to convert toxic Ammonia to Nitrate as fertilizer. Diagram above showing how I place the mediums layer by layer.
1. Top layer with JBL Symec to collect any dirts from the tank.

2. Layer 2 using ADA Bio Rio provides the ideal home for a long term and stable colonization of bacteria and maintain the conditions of aquarium water.

3. Layer 3 with JBL PhosEx Plus binds excess phosphates quickly and reliably without releasing them again, to prevent any algae bloom.

4. Bottom layer is bamboo charcoal to absorb unnecessary substances, excess nutrients and to improve the clarity of water. Its porous surface provides good water circulation thereby prevents clogging and provides home for bacteria colonization.