What happens if CH is very high?

[Brentr]

Happy Easter to all. The wife thinks that we have black algae so I shocked the pool for one week keeping the FC @ 30 and purchased a Stainless Steel brush to try to brush off the darker areas. I rubbed a trichlor tablet on the darker areas and it did not appear lighter.
Here are my numbers today, we have guests so I am concerned in swimming with very high FC.
FC - 20
CC - 0
TC - 20
pH - 7.5
T/A - 70
CH - 775
CYA - 70
Temp 88
SWG - 3100
Borate - 50-80
Thanks for all input

 

[PoolGuyNJ]

Most likely, at 775, you will be forming scale deposits. Time to start diluting or an RO treatment, if available.

Happy Easter!

Scott

 

[Brentr]

Scott what is a RO treatment?

 

[PoolGuyNJ]

Reverse Osmosis,

 

[susa]

Don't know how fillup water test for CH in Jacksonville, but deeper down in Florida, even with a new pool, my CH initially went up to 300 and last test was down to 180 so I had to actually add calcium to slowly bring it up to about 300.

Tested today at CH 250

 

[Brentr]

I just tested the drinking water and the CH is 175-200. Do you think the darker black spots are scaling?

 

[zea3]

How did the CH get that high? Are you using cal-hypo in the pool? Try using a length of PVC to pour MA directly on one of the spots and see if it goes away.

As far as high FC goes, you can swim up to shock level for your CYA. Plug the numbers into the pool calculator to see how much FC is safe to swim in your pool.

Make sure you turn the SWG off when you are ready for the FC to drop back down.

 

[Brentr]

How did the CH get that high? .

I noticed the CH creaping up since the pool build. It started at 375 two years ago and I guess it really went up over the past winter.

Are you using cal-hypo in the pool? Try using a length of PVC to pour MA directly on one of the spots and see if it goes away.

I am using bleach and SWG in the pool. The spot went away after using a lenth of PVC to pour MA directly on one of the spots so do I have some scaling and not black algea????? Do I need to drain the pool to dilute the CH per suggestion from Scott???? Any other alternatives?????
Thanks in advance

 

[JasonLion]

The two ways to lower CH levels are water replacement or getting a reverse osmosis treatment. RO is not available in all areas.

Because your tap water CH level is fairly high, you might want to try getting through the season with very high CH. Otherwise you will be replacing water or getting an RO treatment every year.

 

[Brentr]

Thanks Jason, there will be some water replacement this summer with rainfall as I usually backwash the filter when the pool fills up with rainwater. What would be recommended chemical levels to shoot for? And is it okay to brush the pool using a Stainless Steel Brush instead of the vinyl bristle brush.

 

[Taz]

Brentr: Mine when up a great deal (400 to 500) this winter also even though I maintained the TA & PH fairly well. Must be a NE FL thing.

Regretfully, the rains have missed us so far. Perhaps we can water our lawns with a partial pool drain to even out the cost!

Cheers - Taz

 

[Brentr]

Brentr: Mine when up a great deal (400 to 500) this winter also even though I maintained the TA & PH fairly well. Must be a NE FL thing.

Regretfully, the rains have missed us so far. Perhaps we can water our lawns with a partial pool drain to even out the cost!

Cheers - Taz

Exactly what I was thinking, however Jason thought that I may be able to get by, but I think I need some input in recommended chemical levels to shoot for.

 

[JasonLion]

As CH goes up you need to lower your PH and TA to compensate. You can use the CSI function on the Pool Calculator to help you figure out appropriate levels. Try to keep your CSI at 0.3 or lower and don't take PH below 7.2. The higher CH gets the more important it becomes to never allow PH to get too high.

A wire brush is fine after the first six months to a year from when the plaster was applied, but the best thing to use is a combo nylon and metal brush.

 

[duraleigh]

Double ditto what Jason said.

However, I would personally prefer to lower CH mechanically (partial drain). Your CH would quickly get below 500 (which is very close to the 250-400 we suggest) if you did two successive 33% drain and refills. Subsequent rainfall and refill would make it even lower.

A CH of 500 or less I would consider not at all troublesome as long as you kept your pH in the lower 7's and it would make it unnecessary to calculate CSI.