Good question, and one I was going to ask...although in a different way. How do you know when to change the cartridge? I have always kept mine open to 2. I thought it was time to change but I can still hear a bunch of bromine in it when I shake it. I have it wide open right now. When should I just throw it out? Will it be completely empty?
Elle
If you have it wide open and are still low on Bromine that's part of your problem. Yes it's out and needs replaced. It does take a while to get used to your system but once you do, you will see the bromine level beginning to drop and know that you need to replace it. You should be able to leave it on 2-3 all of the time and be fine. Don't look for perfect color on your test strips as far as bromine level. Your test strips are generic and don't take the ozone and minerals in to account. At 2 on that cartridge you should last about a month 3 will drop it by about a week. When you get a new one, get some granular bromine and hit the spa with a good shot. I would also drain the water if this is the first fill and it will get easier from here out.
The thumping you hear in your cartridge is probably just the leftover filler.
