PH and CH - What am I missing here

[mpride]

My pool was completed in September of last year. Since that time I have had a high consumption of Muriatic Acid. I understand that this is normal early on but was curious when I can expect consumption to subside some? I use about 2 to 3 quarts each week. If this is normal that's fine too but I'd like confirmation from someone just to put my mind at ease.

One other thing I've noticed is my CH levels are rising much quicker in the past few months than it did the previous months. The pool was not closed over the winter and I checked CH during the winter with very little change. I've drained water to get the levels down and here they are above the recommendation again.

My latest test results as of this morning are:

Water Temp = 82
Air Temp = 82
FC = 3.5
CC = 0
PH = 7.8 (before I added MA)
TA = 90
CH = 360
CYA = 55
Borates = 50
Salt = 3100ppm

If I need to test something else let me know.

Any help on this would be greatly appreciated!

 

[JohnT]

Your plaster is probably the main cause of your pH rise, but your SWCG will also cause a constant pH rise as well. I believe your system calls for CYA of 50 to 80ppm. Raising your CYA to around 70 will reduce your SWCG run-time which may help reduce the pH rise as well.

All said, your MA usage is probably on the low side a little considering your situation. Should get better by next season.

 

[257WbyMag]

It can take up to a year for your plaster to cure so you can expect to use lots of acid until you get closer to September.

You also have a cartridge filter. This means you don't have the benefit of backwashing calcium down the drain like you would with a DE or a sand filter. Calcium stays in the water unless it is actively removed by splash out, draining, or backwashing. Be sure to avoid using cal-hypo products in your pool at this point as they will add more calcium and increase your CH. You should also consider the calcium that is being added from the fill water. Have you checked the CH in your fill water?

 

[coog61]

mpride - I am in the Sugar Land/Richmond area with a pool started July 2009. I'm fighting the same battle on CH (see my other posts). I'm now at 440 and this is after draining 40% of the water in March. My fill water (MUD #25) is 130.

Continue to look for ideas on reducing/maintaining this including an additive I found on line (made in Australia) that binds calcium that can be sucked up or adding a water softener in line with a value to put in a % of soft water.

Going to add Borates soon, so will see how this goes.

Regarding acid, I'm also adding about the same as you. About 1 qt every other day.

Happy to compare notes. You can PM me if you like.

 

[Guest]

Your CH is getting towards the high end of acceptable (200-400 ppm), but it isn't real bad yet. Do you have any R/O companies in your area?

I didn't look ( ), but are you pebble or plaster?

 

[mpride]

First off, thanks for all the quick replies with the information. I belong to several online forums (mostly auto related) and I think this is probably the most helpful forum I belong to. Thanks.

I have a quick question about CH. Will high levels hurt the pool or equipment? If not, what is the concern?

JohnT
1. I will try to raise CYA that later this week. I'm currently out at the moment.

257WbyMag
2. Do you know where I might get cal-hypo ? Would that be something in the stabilizer?
3. I will also check my fill water. I should have already done this.

Coog61
It's great to hear from a neighbor. I bet I have the same issue with my fill water. I'm sorry you also have this issue but I'm kinda glad It's not just me.
I will also be taking you up on the IM offer.

simicrintz
It's a plaster pool.
4. Excuse my ignorance but what is a R/O company?

 

[JasonLion]

R/O stands for reverse osmosis. This is a process for removing CH (and everything else) from the water when your CH or CYA levels get too high. Both your CH and CYA levels are fairly reasonable, so I wouldn't suggest R/O.

 

[Guest]

Plaster; got it. I have noticed that pebble pools tend to require greater amounts of acid than the plaster pools do, which is why I was wondering. Plaster curing, as previously mentioned, will keep demand high for a while as well.

R/O is Reverse Osmosis. There may be a company in your area that you could speak with. You can learn more about it from my signature, if you want to read up first! Your levels are not severe enough for this treatment, but it may be something to look at in the future.

Edit: Jason types faster than me!

 

[257WbyMag]

257WbyMag
2. Do you know where I might get cal-hypo ? Would that be something in the stabilizer?
3. I will also check my fill water. I should have already done this.

Cal-hypo is calcium hypochlorite, a granular type of chlorine. It contains no CYA (stabilizer) but it does add calcium to your water and this is something that you don't need any more of. I wanted to make sure that you were not using it becuase I didn't want you CH to go any higher than it already is. For what it's worth, it can be purchased anywhere that pool chemicals are sold and is commonly sold as "shock". It chlorinates quickly, but with the added expense of putting calcium in your pool. You don't want anymore calcium in there.

There's nothing saying that you should have known to check the CH on your fill water so you shouldn't have necessarily already done this. You should know though that this is a source of calcium in many places, including Texas, and that continued filling and topping-off of your pool with tap water that has calcium in it has the potential to raise your calcium hardness and will do so over time, especially if you have a cartridge filter. When I purchased my home that had a pool already installed, the calcium hardness was 650 ppm. The reasons for this were that I had a cartridge filter (no backwash), the average CH for my tap water is around 125 ppm, and the folks that we bought the house from dutifully shocked the pool weekly with HTH Super Sock It (cal-hypo).

 

[mpride]

Continue to look for ideas on reducing/maintaining this including an additive I found on line (made in Australia) that binds calcium that can be sucked up or adding a water softener in line with a value to put in a % of soft water.

Ok. Here is the product that coog61 (thank you sir) was referring to:

http://www.lochlor.com/calcium_hardness_reducer_-_new.html
http://www.toysplash.com/productinf...glebase&cvsfa=732&cvsfe=2&cvsfhu=333030313631

Here are the questions I have about this product:

1. Has anyone used this product?
2. Should we be concerned about using this product?
3. What questions should I ask of the manufacturer to make sure this product is safe to use and won't casue other problems?

 

[JasonLion]

Those are both sequestrants that are optimized for calcium. They don't actually remove any calcium from the water, instead they bind to the calcium and help prevent it from causing scaling. They break down over time and need to be replaced reguarly, so they can end up being expensive.

Since your CH level is just fine where it is, at least for now, there is no need for anything along those lines.

 

[mpride]

Thanks Jason.