we put up the pool 5 days ago. On the second day we took a pool sample to the pool store for testing. Almost no free chlorine & alkalinity was high. Was told pool needed muratic acid then be shocked to help the SWG work. Pool guy said we needed a pound of shock & he chose for us a pound packet to use. Day three we had 2 children and 3 adults in the pool for about 6 hours. Oh, have been running sand filter pump for 6 hours a day & SWG for 5 hours. Day 4 there was very low FC reading again, so I increased run time of each unit by an hour. Still very low FC...hmmm. So, I tried to do a boost yesterday but got a low salt error code on my Intex Krystal Clear SWG. with all the water splashed out & well water added, I thought I needed to add salt, checked sodium with a test strip and it was under 3000, so I put in 40 pounds, ran the sand filter pump 24 hours. Checked chems this morning, salt was on the high side of 3500, alkalinity was high again, ph was ok. FC still low so I tried running the boost again. Got low salt error! So we took another sample to the pool store, they confirmed our test results, especially high salt and said we needed to add muratic acid again then 1 lb of shock. This guy said there is a shock made for saltwater pools. What we added the first time was not the right stuff. So long story short, our low salt reading is probably from the calcium in the first shock chem. too dark now, but will check the SWG tomorrow morning to see if electrofiliments need cleaning.