This year when I opened my pool it was dark green. This was the worst in all the years I have had the pool. I began adding lots of liquid bleach as well as calcium hypochlorite in an attempt to get a free chlorine level. Finally, after several days, I seemed to be getting somewhere. However, I couldn't seem to get chlorine level to hold. I brought a sample to Leslies today and the FC level was 0 and CC was 1, CYA 10, PH 7.4. They told me I had "chlorine lock" and talked me into getting MPS. This seemed counter to what I have read here but they somehow convinced me to get it. I added it and later my FC level did rise, using DPD 1 tablet. I don't plan on using it anymore. Do I have anything to be concerned about? Will there be any residual chemicals from it? How long will it affect the DPD 3 test? I plan to convert to SWG once I get the pool clean.
Thanks for your help.