Should I lower TA?

[Poolecw]

First time pool owner here, but have been following the TFP forums for a year or so.

Our new pool was filled with tap water two weeks ago. I tested the tap water before any chemicals were added and TA=200 & pH=7.5.

After two weeks, my numbers look like this. Should I work to lower it or let it ride for a while? MY pool builder said to let it go as the rain will bring it down.

SWG@80%; 1750rpms (I have been keeping the pump at this speed 24/7)

FC=7.0 and rising. (I think I may drop my SWG to 60% to slowly start bring FC down)
CC=0.0
pH=8.2 and slowly rising
TA=150
CH=100
CYA=30 (CYA has been slowly increased to this but has been too low to read)

 

[splashpad]

First time pool owner here, but have been following the TFP forums for a year or so.

pH=8.2 and slowly rising

Great to have you here!

I would use MA (muriatic acid) to bring PH down to 7.4. It will make your FC more effective and also prevent scaling.
MA should be poured low and slow in-front of a return (water coming into pool)
We prefer to watch PH and not "aggressively" chase TA numbers (those will level out as the PH is adjusted)

 

[mguzzy]

yes, you are on the right track. I think I would drop your SWG to 50% a and the keep and eye on it. Also I would add some MA (use pool math to calc the amount) to below 7.8. That will also drop your TA when you do that. SWG's inherently raise the pH.

Edit: Splash recommended a pH of 7.4.. that will work to. I suggested 7.8 because a lot of SWG chlorinated pools seem to stabilize there. But on second thought 7.4 might be better since you are still in your first two weeks with the pool

 

[Poolecw]

Awsome guys. Thanks for the advice. I'll add the MA today.

 

[Poolecw]

Well.... I didn't get the decrease to pH that I was expecting. I could not find any MA, so I used a product called pH Down (93.2% Sodium Bisulfate). I added 40 oz, which was slightly conservative from the directions (50 oz).

24 hours after adding, here are my results:
FC 5.0
CC 0.5
pH 8.0
TA 140
CYA 30

Perhaps my TA is such a large number that pH isn't reacting as much with the product I added.

Any suggestions? Should I find some MA and give it another shot per Pool Math recommendations?

 

[splashpad]

Well.... I didn't get the decrease to pH that I was expecting. I could not find any MA, so I used a product called pH Down (93.2% Sodium Bisulfate). I added 40 oz, which was slightly conservative from the directions (50 oz).

This adds sulfates which do not play nice with SWG (in fact most SWG manuals strongly warn against the use of dry acids).

Any suggestions? Should I find some MA and give it another shot per Pool Math recommendations?

It should be in the paint section. Walmart has a diluted version, but most hardware stores will have the full strength 31%. Just be sure there is a % strength on the bottle, so that it is not any other chemicals.

 

[mguzzy]

Well.... I didn't get the decrease to pH that I was expecting. I could not find any MA, so I used a product called pH Down (93.2% Sodium Bisulfate). I added 40 oz, which was slightly conservative from the directions (50 oz).

24 hours after adding, here are my results:
FC 5.0
CC 0.5
pH 8.0
TA 140
CYA 30

Perhaps my TA is such a large number that pH isn't reacting as much with the product I added.

Any suggestions? Should I find some MA and give it another shot per Pool Math recommendations?

I wouldn't worry so much about the TA.. You are in a decent range. Just keep your pH in range. for an SWG most people find 7.8 works well since pH rise is a part of life with a SWG. Then the TA will settle to its own level in relation to the pH.

 

[Poolecw]

This adds sulfates which do not play nice with SWG (in fact most SWG manuals strongly warn against the use of dry acids).


It should be in the paint section. Walmart has a diluted version, but most hardware stores will have the full strength 31%. Just be sure there is a % strength on the bottle, so that it is not any other chemicals.

The product I used specifically said it was salt water compatiable. LOL. Oh well. I'm going seek out some MA and try again.

Thanks for the help.

 

[tim5055]

You will find MA at Home Depot in the paint department.

 

[mguzzy]

The product I used specifically said it was salt water compatiable. LOL. Oh well. I'm going seek out some MA and try again.

Its compatible with the salt water, but not with the salt water chlorine generators.

I would be interested if you post a pic of the side of the bottle that says that... it would be a good info to share here.

 

[Poolecw]

Here is a picture. How much damage have I done?

 

[mknauss]

Don't use anymore of the sodium bisulfate. As you get rain I suspect your pool overflows occasionally and thus the sulfate level will drop.