Should I replace my water?

[Mirage21]

FC - 5
PH - 7.4
TA - 100
CH - 475
CYA - 60


My CH has gone up from 400 last month to about 475. Wondering if this has anything to do with rain? I had replaced some water that evaporated over the last couple of months, but it was only about 3-4 inches worth. (Rain filled the pool to the top tile mark, but it drained to about 1/4th mark on the 6 inch tile, then i filled it up).

Should i replace some water? Pool calc says 16-26% for a 350-375 range for CH.

I have some scaling on the tile as well, but easily rubs off with the eraser.

 

[duraleigh]

It sounds like it's fairly easy for you to replace some and it would get you into a more comfortable range on CH so I would do it.

Importantly, make sure your pH stays down in the 7's where it is......that'll help reduce or eliminate the light scale you have.

Overall, pretty nice numbers except for your CH up on the borderline.......I'd lower it just like PoolMath says.

 

[Mirage21]

It sounds like it's fairly easy for you to replace some and it would get you into a more comfortable range on CH so I would do it.

Importantly, make sure your pH stays down in the 7's where it is......that'll help reduce or eliminate the light scale you have.

Overall, pretty nice numbers except for your CH up on the borderline.......I'd lower it just like PoolMath says.

Thanks, this pool is about 3 months old now (re-plaster). Should I be concerned with anything (i.e. waterline marks, additional scaling, cracking, if i drain 20% of the pool and re-fill at this point?)

So when water evaporates, does it take the CH level with it? I'm asking because if i had already added more water, shouldn't the CH level go down as i fill it back up (dilution)? Or is this a constant factor due to the water coming in already at a certain CH (e.g. 400 from tap).


My PH keeps rising, with no stability in sight. Hope it "stabilizes" soon to the point where i'm not trying to add a gallon a week of MA. (By that, i mean adding less MA over longer periods to keep the PH in range).