I purchased some Ahhsome filter cleaner from Amazon and it just came in today. (I have been using the hot tub cleaner from them for over a year now and love it) I am planning on cleaning my cartridges tonight. It says on their website that I only need to let them sit in a bucket with the ahhsome in it for 15 minutes. Is there any harm in letting them stay in the cleaner longer? I just think 15 minutes is a bit quick. I don't want to ruin my cartridges. Thanks in advance for any assistance.