I have been dealing with this problem and it's relentless. The water was pristine and clear. It was five weeks after I had initially changed the cartridge and thought to change it to a new one. Since then the water is murky and cloudy.
The water parameters are fine. I even would do a 10 - 20 percent water change every 2 - 3 days and still cloudy.
It was recommended at the time to switch to this: https://www.amazon.com/Tetra-EasyBal...ct_top?ie=UTF8
I even used Prime too, as it was considered the best option, but I guess because I was water cycling every 2 - 3 days, I probably overdid it with prime and messed it up more.
I have been using Tetra because Amazon obligated me to be two - which came to $9.99, so I have two 16 ounce bottles to go through.
But the water still remains cloudy. I never had this problem with the API products.
So because I have a litltle API tap conditioner and stress coat, I just added those with the water change just now. I would also use quick start as well.
But this 4 week cloudy water persists. I even cleaned out the filter, which I understand is not something we should do, but I was desperate. I lost one fish this morning.
Could someone tell me why I don't have pristine water like before? It's really upsetting. Should I just use the Tetra once a month and do the API with every water change? I cycle the water every 3 days or so because of the fish waste.
I just wanted to add that the Terta has 4/5 stars on Amazon and the 1/5 stars did complain that the water immediately clouded as soon as they added Terta, but they did not say what they did to clear it - unless it's assumed they never used it again.