Scale, I need help please

[needsajet]

I would do the borates because your scale issue is perplexing and I'm interested to find out if it helps. It won't hurt the plaster so all good there. If leaving your TA high, delay your CH increase until it's needed to balance CSI.

Ignore the rest of what I say...

A lot of people would say don't worry about lowering the TA anyway. Most of what lowering it will do is spread out the frequency of acid additions. If you're away a lot, that can be important. There are some writings that say lower TA reduces the amount of acid needed to counteract the pH rise from an SWG, but I haven't read anything yet that convinces me. On the other hand, I could believe it because some of what goes on in the guts of an SWG cell housing is poorly understood.

If you want to spread out the frequency, you can go lower when you lower your pH, to 7.2 for example. This will cause slightly higher acid consumption, so it's a convenience vs. cost thing. It won't be a huge amount more acid. I've seen some chem equations that suggest to me that in the long run, it isn't any more at all. It's just X TA in = Y MA to counteract it. But it's not within my grasp yet.

It makes sense though, because why would taking your pH lower once a week be any different from the TA lowering method? It's just on a slower cycle time because of slower aeration.

If you want to reduce cost, lowering TA aggressively may just cost a bunch of electricity for aeration. It will happen on it's own from the in-range acid additions. (and some from rainfall as pooldv mentioned, which is free!).

If you want to fit the recommended ranges sooner rather than later, you'll notice a "+" after the 90 in the recommended ranges. So to me it's like it is for the high CH people. They go above the recommended CH number, and adjust TA and/or pH to keep their CSI where they want it. People with high TA water can successfully run their pools at high TA by reducing CH and/or pH to keep their CSI where they want it.

On new plaster, I think near 0 or slightly negative is good. For you with a weird scale issue, a bit more negative (-0.2) is probably better, but hey, we're talking tiny differences and we're in ghostbuster land anyway, right?

 

[bdavis466]

Nothing wrong with -0.2. Give it a shot.

NAJ- it can't be a good thing that I'm posting at the same time you giving our locations... See you in the morning

 

[needsajet]

True dat! Sleep well, Brian

 

[pooldv]

Rain water capture might also be a good way to get more fill water with TA under 300.

 

[Lykly]

I have significant water features, two large water falls and a large fountain I can operate, will that help raise my ph if needed? Just want to know exactly what what to expect before I add anything since once I do it is a done deal. I think I will start with 30 ppm on the borates to get a feel for them, Thx


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[pooldv]

Yes, those should raise PH plenty.

 

[Lykly]

This whole pH rise for one year of curing plaster is a myth. Rapid pH rise will occur for the first 3-4 weeks after the plaster has been applied. It should have reduced significantly after the first week and then again each week following. Please don't get your hopes up that in one year your plaster will have magically reached its happy state and will no longer contribute to your acid demand.

I have already seen this to some extent. If I were not trying to keep my pH down around 7.2 and 7.3, it would not require near the acid I am using. I am only doing that to try to lower the TA. If I let it be, I'm not so sure that it wouldn't hang around the 7.5 to 7.6 range quite easily. That seems to be the point where it like to settle in at. I will let it go today just to see what it does.

Here is another interesting bit of data:
I have a hot tub, that is completely separate from the pool. It is the same fill water only exception is on fill it went through my softener so is basically no hardness in it at all. It also has a saltron mini salt water generator, which is been in there a long time. I never touch the water, I bet I haven't added acid to it maybe once a month a month, other than that I don't touch it. And I've never seen scale.

Current numbers in my hot tub are:
C 4
TA 40
Ph 7.4
CH 75
Salt 3200


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[Lykly]

I received my borate acid granules today, my TA at 100. I think I will continue to lower it a bit before adding. Also my new Hayward cell should arrive Thursday, so I thought I will change it out see what happens before I make any other changes. I have to admit, I am impressed by Hayward sending me that new cell to try.



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[pooldv]

Yes, that is a good idea to wait and have apples to apples comparison for the new cell.

 

[Lykly]

It will still be a while before I can report on how the new cell performs, they mistakenly sent me a T3 cell. They are sending me the T15.


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[needsajet]

Rats!! That's disappointing!

 

[IsaacFL]

I received my borate acid granules today, my TA at 100. I think I will continue to lower it a bit before adding. Also my new Hayward cell should arrive Thursday, so I thought I will change it out see what happens before I make any other changes. I have to admit, I am impressed by Hayward sending me that new cell to try.



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I just stumbled on this thread, but I also have this same problem with piles of white flakes forming in piles. I believe it is definitely produced by the salt cell, because I can see the flakes coming out when the cell is on. It tends to form in piles in calmer areas near the returns. My cell is a Jandy Aquapure 1400 in a pebbletec poolfrom 2007 era.

My fill water from the city has a TA of 150 and CH of 175. My problems started when the water temp rose to 91 and the full sun has made me increase the cell to 75% for about 6 hours.

I currently have a problem of high CH at 775 so I am struggling to keep my CSI in check since my pH rises so fast. I can add acid to get to 7.2 and within 24 hours the pH is around 7.7. I am considering adding borates so watching this thread to see if it will help.

 

[Lykly]

My fill water from the city has a TA of 150 and CH of 175.

I currently have a problem of high CH at 775 so I am struggling to keep my CSI in check since my pH rises so fast. I can add acid to get to 7.2 and within 24 hours the pH is around 7.7. I am considering adding borates so watching this thread to see if it will help.

Curious as how you're CH is 775?
Sounds like a similar problem with scale the way you describe it, I don't know that I would add borates with the TA at 150. What is your CYA level?

I'm going to wait and change out the cell once they send the new one before I make any other changes. I also want to get my TA below 100 before I add borates so I don't have to worry about battling the pH. From what I understand, it is more difficult to lower the pH (to lower TA) once you have borates. Keep watching this thread hopefully you can learn something thy helps you, also if you figure it out let us know.



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[pooldv]

Some of those California and Arizona folks have crazy high CH. Some 1200 and higher. High CH fill water and low rainfall is a recipe for high CH.

 

[IsaacFL]

Curious as how you're CH is 775?
Sounds like a similar problem with scale the way you describe it, I don't know that I would add borates with the TA at 150. What is your CYA level?

I'm going to wait and change out the cell once they send the new one before I make any other changes. I also want to get my TA below 100 before I add borates so I don't have to worry about battling the pH. From what I understand, it is more difficult to lower the pH (to lower TA) once you have borates. Keep watching this thread hopefully you can learn something thy helps you, also if you figure it out let us know.



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I am not sure either but I am assuming it is due to the high CH in my fill and our high evaporation right now. We have had are about 110F everyday now.

Where is my CH coming from?

I posted a thread but never really got a good answer. I am probably going to have to do a partial drain in a few weeks as I am having trouble keeping the CSI in check now.

 

[bdavis466]

Your CH rise is from evaporation and refill. That is very common in the southwest because of the high daytime temps relative to the low nighttime temps and fill water with normal to high CH levels. Every drop you replace from evaporation adds more calcium to the pool.

I have to drain 1/2 of my pool every year because of CH and salt levels. My CH rises by about 150 (or more) per month and I am currently at 750 with a CSI of -0.2. I have never had scale and have never cleaned my salt cell.

TDS is pool store and pool service workers way of saying that they don't really know what's going but it gives them an excuse to drain. I've never tested mine but based on my numbers, it's well over 5500. I don't know what that means and I don't care because I know what is actually making up the TDS value and can adjust them to compensate for elevated CH levels.

The warmer you water gets, the harder it is to keep your CSI negative. Limiting evaporation by using a pool cover will all but eliminate the CH rise you are experiencing but will make your water that much warmer.

TA has a huge impact on CSI. Lowering your TA to 50 would allow your CH to climb much higher yet still be negative on the index.

Borates help the CSI by making it 0.1 to 0.25 lower than where you are without them. They also are a good addition for preventing pH rise - especially within the swg cell. The only trouble if you choose to add borates is that will be another expense to replenish in your water after a drain and refill.

RO for your pool seems like a good thing but is very expensive and wastes 15-30% of the water anyway. Refilling half of my pool is barely noticeable on my water bill. Your pool is 1/5 the volume of mine likely a very small expense to refill.

 

[IsaacFL]

My TA is currently at 70, so lowering would probably help. I just did a complete drain about a year ago, and the water bill was only increased by $10.

My pool is not set up to drain easily though. What I am going to try to do, is get a fitting for my cartridge filter so I can connect a PVC line with a shut off valve so I can start doing partial drains while vacuuming.

As far as the scale, I know it is caused by the cell because I just turned it off for a few days and switched to bleach only. The scale stopped forming.

My theory is that the local temp of the water inside the cell rises to the point where the local CSI is too high and forms scales which then get blown out.

At my CSI level it only takes a 10 degree change to make a difference.

 

[bdavis466]

It isn't so much the temperature change within the cell but aeration from Hydrogen gas formation that is the culprit. This is why borates reduction of pH rise, especially at levels close to 8 dramatically reduce scale formation. It's safe to assume that whatever the CSI is in the bulk pool water, it's +0.3 higher in the cell.

You can see that by borates limiting the pH rise in the 7.8-8 range will help significantly and if the pH is much lower than that, the CSI is likely low enough to prevent scale formation.

Again, I've never seen a single flake from my swg but I monitor CSI very closely.

 

[chiefwej]

I am always dealing with high TA and very high CH. When I first came to TFP, I had scale on pool surfaces and my water often looked like a small snow storm, (with all the flakes). Right now my CH level is well over 1500, and there is nothing I can do about that short of draining the pool. But with acid and aeration I dropped the TA from 250 down around 70, added borates to further help stabilize my pH, and keep my CSI right about -.2 or -.3, and my scale and flakes are no more.

Once the hottest part of summer is past, I will drain the pool and refill. But I'll still be restarting with fill water with a CH over 350 and a TA around 200. Rapid evaporation here in the desert will put the CH back over 500 in no time, and the battle begins anew.

Persistence is the key.

 

[Lykly]

I am hoping lowering TA and then once that's accomplished adding boric acid granules will eliminate the scale. Just need to figure how low to get TA.... Sitting at 100 now from nearly~300 at start.


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