JBL PhosEx Ultra: 2.0 mg/l of phosphate comes out from my faucet. My question: Does the filter medium last during water changes when it is in an absorptive state, or does it have to be replaced each time?
JBL PhosEx ultra binds approx. 18,000 mg of phosphate before its capacity is exhausted. That is why, even when a water change is done, it can still be used until its capacity has been exhausted and the phosphate concentration in the water rises again (check with JBL Phosphat Test sensitive). 2.0 mg/l in the tap water yields 400 mg phosphate in a 200 l tank if a full water change is done and 200 mg new phosphate if a 50 % water change is done. Therefore, you can calculate the approximate range.