Should I use Scaletec or not?

Dec 14, 2010
3
Scottsdale, AZ
First off, great site, and the iPhone App is cool Jason! (when is the Borate calc coming? ) :cool:

So here's the story; our pool is going on three years old. 13' x 28' x ~4.5' infinite edge with a 3.5' x 26' x 2' overflow sump which equates to around 13k gallons total. SWG, Pebble-Tec, Sand filter and CoverPool automatic cover. I'll attach a couple of pics here if I can in a bit.

About six months after startup, we began noticing scaling starting at the bolt holes on the infinite edge where the CoverPool track is installed. The track is mounted to stainless steel standoffs that were drilled down through the tile. I had been using test strips (first mistake) since the inception and had felt that I was keeping things well enough in check. My assumption was that the CoverPool install guys had not sealed up the holes well enough and so the scaling was a direct result of leaching from the concrete wall underneath. Things have gotten steadily worse to the point one of the tiles on the edge actually popped off as it was lifted by the scale underneath. Other scale streaks are running down the outside back wall of the edge which is covered in Pebble-Tec. I was prepared to go to battle this spring with MA or media blasting to clean the mess up.

I had my above ground spa worked on earlier this week, and the tech inquired if I had any issues with the infinite edge, to which I complained about the scaling. After he looked at it, he said it was due to poor chemistry, that the test strips were not the best, and to get things in order and try Scaletec to loosen things up.

In my Googling of Scaletec, I stumbled upon this site and the rest is history. Tuesday I went to Leslie's and got a Taylor kit and here is what the initial readings were:

FC = 5
CC = 0
pH = 8+
TA = 170
CH = 240
CYA = 35
Salt = 3200
temp = 55*

Running my aerator and edge pump continually (shut off SWG for now) over the past couple of days I've managed to bring TA down to 90 as of this AM and CYA is 50 and rising. So far it has taken ~3.5 gallons of MA. My goal is to get TA down to 60, and then shut down aeration, get pH to 7 or below (no heater, cover fully retracted) and begin the Scaletec treatment. Does this sound like a good plan?

My own well is the source of the water (although the inital fill was about 50/50, hauled Scottsdale City water/my well) and here are the readings out of the tap:

pH = 8+
TA = 170
CH = 0 (a bit odd for AZ well water I *think*)

As a secondary question, and I know it will vary by season, but how should I gauge the amount of time to run the edge pump to sanitize the ~1,600 gallons in the sump? Seems like a fine line between adequate filter time vs raising pH. Seems like Borate might be a possibility to help buffer this situation...

These pics were taken not too long after startup, as the wok pots were not done yet and the temp pool fence was still up. Note in the overhead shot the start of the scaling on the blue edge tile, which started at the CoverPool track bolts:
 

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Get your pH down to 7.2 and hold it there for several weeks. Do not go below 7 for any extended time, especially if it is being used. Your CH is good (great) so you just need to get the build up (most likely caused by your high pH) back in solution, which it will. Then do not allow your pH to rise up that high again.

If it were me, I'd save the money on the ScaleTec and get your water where it should be. You should be just fine after that.
 
Other than your PH and TA, all your readings look pretty good. I am a little amazed at how low your CH for being in AZ. You really need to bring your PH down 7.2 - 7.4 along with TA under 120 ppm that will help with some of the scaling. I really have not used Scaletec, but based on this site, less is more. As for your tiles popping off, I would bet the contractor did a poor job of setting the tile and "NOT" the scale causing the problem.

Last I looked Borate Calc is in the App...

Simicrintz beat me... Dam he's fast!!!!
 
Thanks for the quick reply.

The pool is not in use this time of year, so I'll try and keep the pH in the 7.0 range and see if the scale is re-absorbed.

Any recommendations of how long to run the edge pump to keep the sump water in decent shape? I've been running it an hour a day while the main filter pump is on, but it must create quite the amount of aeration...
 
I missed the part about the tiles popping off (sorry :oops: ). Doubtful it was the ScaleTec, but pretty sure it is the extreme heat differential you experience in your neck of the woods! That V-Edge wall most likely gets really hot in the summer, and then you go dump water over it that is 10's of degrees cooler. Expansion and contraction values come in to play and you get popped tiles!

Most likely cheap setting material (thinset) was used. You really need a Full Flex product for applications like that, and even then you could experience problems. Those tiles get so hot, and expand so much, only to be hit with "cold" water, which then contracts the tile, eventually "snapping" the bond.
 
Well, the heat on the tile could play a part, but I'll try and get some better (current) pics to show the true carnage! The scale is really quite bad now. But ONLY on the knife edge, which emanated from the track bolts.

I have not used the ScaleTec yet, and I think for $40 I'm going to be returning it to Leslie's.
 
That edge is exposed to the heat, so it gets dried out daily. Calcium likes to stick where water is moving, and it builds on itself. That nice, big weir, with water running over it every day, gets deposits of calcium every time the system runs. Then it shuts off and the calcium sets up and hardens and waits for the next time the system starts again. The same stuff happens on raised spa spillways and waterfalls.

Be prepared for a battle at Leslie's on the return :evil: Good chance you'll get the "I'm sorry, but we cannot take chemicals back; it's the law" spiel. I'd start in with a good attitude and hope you get someone with some compassion!
 
I am currently using ScaleTec Plus and I am seeing fairly good results. I think I will make ScaleTec part of my routine maintenance

Backstory: I have a concrete/gunite in-ground pool with white-blue Diamond-Brite plaster. It is a chlorine pool, which is 2 years old, 15,000 gal. It is partially shaded. It had some older lime scale from (I suspect) improper initial startup from 2 years ago. My pool guy (who I have since fired) was calling these older scale spots "grey mottling" and would always say that it was easier to prevent them than to treat them. He never treated them. However, this summer my pool also developed regular calcium scale. It became very unsightly. My research leads me to believe that the calcium scale formed due to the very hard water we have in Houston, TX in addition to my lack of proper maintenance. I dropped the ball on my weekly maintenance this summer, so the pH in the pool was creeping up and was high (8+) most of the time. In combination with high calcium content in the water, serious scaling formed in a matter of 2-3 months. My scale spots were extra unsightly because I had an algae problem concurrently and some of the algae color was trapped in the scale causing them to look greenish/yellowish. They blurred together with the "mottling" which I had from before. The majority of the stains were on the pool bottom around the egdes of the pool. Few were on the walls. My initial research was pointing me to mustard algae as the primary culprit. After some experimenting (i.e. trying chlorine treatments on specific spots), it turned out it was not algae. In the end, after a lot of trial and error, I convinced myself that it was calcium scale. Separately from the calcium scale, I had a couple of large brown iron stains caused (I suspect) by my pool heater in areas around the water returns. The reason why I believe these were iron and not copper stains is because they reacted very well to a vitamin C tablet. Hence my plan to combine scale treatment with ascorbic acid treatment.

The treatment which I applied was as follows:

1. Drop the acidity/pH to around 7.0 and keep it there.
2. Drop the free chlorine to 0 just prior to the ascorbic acid treatment (being middle of summer in hot-house Houston, the algae returned immediately but I ignored for a couple of days while doing the metal stains treatment).
3. Treat the iron stains with ascorbic acid (vitamin C) for 24 hours. Concurrently use ScaleTec Plus in addition to "Metal Out" as metal sequestrant in the ascorbic acid treatment. [Off-topic: ScaleTec and Metal Out look exactly the same. I don't know what the active ingredient in either product is. Seems like both manufacturers refer to it generically as a "polymer" but they do not list the chemical name on the label or any of the promotional materials. So far I have not been able to track down the actual chemical name of the active ingredient. It appears that the manufacturers want to make it sound like it is some special magic formulation.]
4. Raise the chlorine gradually (by using liquid concentrated unscented Clorox bleach) to normal levels over 2 days. This took care of the resurgent algae.
5. Pour a double-dose of ScaleTec Plus to work its "magic" on the calcium scale.
6. Spot-treat the hardest/darkest calcium scale areas manually with a spot-treatment tool with muriatic acid. The spot treatment helped as far as getting instant gratification and seeing immediate results, but it was very slow, tedious and it took about 1 hour to treat a couple of square feet.
7. Pour in additional 8 ounces of ScaleTec weekly.
8. Maintain the water balance normally, with pH slightly on the lower end of the scale around 7.0-7.2 (using muriatic acid).

So far, in about 2-3 weeks, I notice that 80% of the scale is gone. If it continues this way, it may completely clear out the pool and make it look better than new. I will try to write an update in a month or two. This website has been extremely helpful for me, and I am trying to share my experiences in order to add to the materials available. But so far I am very happy with the ScaleTec Plus product and will make it part of my regular maintenance. My reasoning is that when you have hard water like we do here in Houston, the only way to counter the calcium is to find something which keeps the calcium in suspension. Otherwise it scales up immediately, especially if you neglect some of the maintenance and let your water balance get out of whack. I know it is easier to say that you should never neglect maintenance and check all measurements daily, and brush the pool all the time, etc. It's just not how it works for me. I am not a pool professional, just a regular end-user and I do not find pool maintenance enjoyable.
 
The key to controlling scale is careful monitoring and controlling CSI. CH tells you how much calcium is in your water, CSI (Calcite Saturation Index) tells you if that calcium will remain in the water or precipitate out as scale. If you put all your test results into Pool Math you will find the CSI calculated near the bottom of the chart. This index is calculated based on CH, TA, pH, temp, CYA, etc. The one factor you have the most control over is pH. You can avoid building scale by maintaining a CSI very close to zero. Adjusting your pH is important because it is how you contro CSI. But looking a pH alone without looking at the CSI is just shooting in the dark, without knowing what your target should be.

I had some scale buildup in my pool, when I came to Trouble Free Pool. Upon discovering the importance of CSI and how to control it, I made it a point to maintain a slightly negative CSI (between -0.1 and -0.5) and over a period of time my scale just disappeared as it was dissolved back into the water. However, you need to be very careful that the CSI does not go below -0.6, or you risk damage to the pool plaster and grout.
 

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The same negative CSI that allows calcium carbonate scale to dissolve also dissolves calcium carbonate scale from plaster. The difference is that for fresh scale on the surface it can redissolve more quickly than the calcium carbonate in between the calcium silicate in pool plaster, but it IS dissolving as well. So you don't want to keep the CSI too negative for too long. A CSI of -0.6 has one-fourth the level of calcium carbonate saturation but -0.3 has one-half that saturation level. It's a logarithmic scale. Lower pH accelerates the dissolving process.
 
Most of the time my CSI was kept between -0.06 and -0.25, so I doubt there was any damage to the pebbletec. It would seem that the recently deposited scale would be softer and dissolve much easier and quicker than the plaster.
 
I am going to throw my name into the mix here as well as a scale guinea pig. As Chiefwej mentioned above, I too was guilty of not properly managing my CSI. My pool water has always been crystal (TFP) clear with a CH of about 250 - not bad at all. And because my pool is fiberglass, I gave little attention to the CSI, I just wanted clear water. However I allowed my pH to remain a bit on the high side all last season and earlier this year. Then the "light bulb" finally went-off this season when I noticed the chalk, faded-looking substance on my pool surfaces. :brickwall: Now I maintain my CSI in the negative. Because my pool is FB and I have no heater or equipment other than my pump, I can get away with my negative CSI a little better. On a whim, I also decided to experiment and added one bottle of Scaletec a couple days ago. Even though they say to give it 4-6 weeks, honestly I don't expect any miracles with that product, but we'll see. More than anything, I expect the lower pH to do its job over time to pull the scale off of the pool surface. I'm tracking everything on my spreadsheet and plan on reporting my progress either here on this thread and/or another thread of a fellow FB pool owner who is working on a scale issue as well. Just another "live & learn" lesson I've had to deal with. At least now I know how to manage it properly. :)
 
I am currently using ScaleTec Plus and I am seeing fairly good results. I think I will make ScaleTec part of my routine maintenance

...

So far, in about 2-3 weeks, I notice that 80% of the scale is gone. If it continues this way, it may completely clear out the pool and make it look better than new. I will try to write an update in a month or two. This website has been extremely helpful for me, and I am trying to share my experiences in order to add to the materials available. But so far I am very happy with the ScaleTec Plus product and will make it part of my regular maintenance. My reasoning is that when you have hard water like we do here in Houston, the only way to counter the calcium is to find something which keeps the calcium in suspension. Otherwise it scales up immediately, especially if you neglect some of the maintenance and let your water balance get out of whack. I know it is easier to say that you should never neglect maintenance and check all measurements daily, and brush the pool all the time, etc. It's just not how it works for me. I am not a pool professional, just a regular end-user and I do not find pool maintenance enjoyable.

ivodjambov, I know this is a 5 yr old post. Just wondering how it all turned out and if you were able to keep the scale away. If you did it by just being more careful monitoring your CSI , or if you added something to the routine (ScaleTec or otherwise). I am also in Houston, and have some recurring scale issues, my pool is "Tahoe Blue" and anything white shows up like you wouldn't believe. Thanks!
 
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