Green pool

[CarlD]

CH is not very important in vinyl or fiberglass pools, because the calcium in the water is to prevent it from eroding morter, grout, plaster, and concrete. Generally lower is better in vinyl and FG pools, but anything below 400ppm should be fine, so don't worry.

[lande]

THE WATER IS GREEN NO MORE!!! Not only that but the water is clear. We have been trying to lower the TA s l o w l y. The green band that was all the way around the pool has turned brown and seems to have disappeared in the shallow end. There is a residue in the pool around the edge mostly and is most evident first thing in the morning before the pumps come on. The DE filter has been cleaned and recharged. Is what I am seeing the residue from the sand algae? Or could the filter be leaking DE into the pool?

Today's readings: FC 4.5, CC .5, TA 120, CH 120, CYA 35, Ph 7.2

[PoolDoc]

DE leaking into the pool will usually appear as a tan to light brown dust accumulating in corners or crevices. If you collect a bit with a dropper, it will feel slight like DE, not sand, and it will NOT dissolve in vinegar.

Sand algae residue can be tan to darker brown, and if it comes off as particles, will (a) feel like sand between your fingers and (b) WILL dissolve in vinegar.