Plaster Dust

[Mackhatter]

Hello! My first post (of many, I’m sure). We’ve owned two inground pools, but our latest (9 months old and an indoor pool) is our first plastered pool. My question is how long will I see plaster dust as I do my routine brushing of the interior surfaces? Eight months into it, I still see dust (although not as much as in the beginning curing process).

I’ll start with that question and then we’ll move to my laundry list of questions about plaster and water chemistry. I’m sure I’ll provide endless entertainment for everyone with my new pool adventures. I hope it can settle down to a routine soon.

Thanks for any help you can give, and here’s a teaser for my next installment: never expect a pool and spa company to necessarily have an employee who knows what they’re doing, service your pool....

Cheers!

 

[justinc]

I am surprised that you're still seeing dust 9 months after construction. I have a newer pool that is plastered and the plaster dust seemed to die down significantly after the first month. What test kit are you using and what are your latest numbers? I would be careful with the Rainbow chlorinator especially with an indoor pool. Using tablets in your in-line chlorinator for routine chlorination will cause your CYA to rise significantly which should be kept very low in an indoor pool. How do you chlorinate your pool most of the time? Tablets or liquid bleach?

 

[Mackhatter]

Thanks Justin. I’m using tablets exclusively with an occasional shock (lightly) with Bioguard Smart Shock.

Your answer prompts me to give my next installment on my adventure. I turned the maintenance over to a company, and they took care of everything except brushing. I looked at their chemistry reports and everything was within limits. I did however check and monitor the PH levels, and found that they would rise into the 8.0 zone if I didn’t continue to add muriatic acid regularly. And probably by regularly meant about a pint a day. I would comment about the acid demand to my PB but got no response back on it- meaning to me it must be normal. Finally, after buying cases of acid over the last 7-8 month,, I decided to become a chemist and truly learn about the test kit and water chemistry. Imagine my surprise when I found out I had a calcium hardness of 900. I stopped right there, went to a different pool store and got the news that yes, I had to drain the pool and replace the water. I’m in a rural area and on a well, so it could have been worse.

Since I had to drain the pool anyway, this was an opportunity to address a tiny rust spot in the plaster. The PB came out and did a great repair, but commented on the appearance of the plaster. It had a mottled appearance and hues of blue in it. The PB said that was from the heater’s heat exchanger. Also, there was some brown from iron in the water. Long story short(sort of), the heater gets bypassed, pool gets refilled and in goes 6 gallons of acid and a brush-o-rama for four days bringing the plaster to new appearance.

Now comes the raising of the PH. It took a ton of baking soda to get it back up. Now to test the water. PH is 7.4. Calcium is low- as expected. And the TA is about 340. What? Guess what? Half the water gets drained again. And yes, I have great well water with low metals (but I used metal magic to be safe). Refilled the pool and got the pH to 7.4, Calcium low, but am bringing it up to about 220 but the TA is at about 200. I plan to bring that down by the lower PH/aeration method, so I think my chemistry adventure is coming to a close- I hope.

So now that I have given the plaster another acid treatment, I suppose I should expect it to indicate as if it was a new pool, with dust showing with daily brushings for awhile??? Then it should diminish to next to nothing in about a month? And if it doesn’t? You see where I’m going with this, right? The second pool supply store mentioned there might be an issue with the plaster. In mentioning it (gently) to the PB, I got crickets. All I can do now is see if the acid demand continues and respond accordingly, but that won’t be daily acid addition.

So gang, there it is, my story. Sorry it was so long. Glad I found this place, and grateful for any help. I have also learned not to put my prized investment into the hands of anyone who didn’t pay for it.

Finally, regarding the chlorine, I’m going to switch from tablets to the forum’s recommendations. Thanks again for any and all help!

Bill

 

[Mackhatter]

 

[justinc]

The taylor 2005 is good but you are missing the FAS-DPD chlorine test. FAS/DPD Chlorine & CC's test Instead of buying an all new kit I would just buy this one for $30 and you'll have what you need. I would use your current kit to test your CYA and make sure you're not over 20 for your indoor pool after having used pucks exclusively. Make sure you test your CYA and stop using pucks ASAP especially with an indoor pool.

 

[Mackhatter]

Thanks, the pucks are out and I’ll order that addition to the kit. I checked my CYA and it was virtually zero.

 

[Jimrahbe]

Mack,

Plaster dust should have been long gone by now...

Using the kit you have, please post a full set of current test data as follows..

FC
CC
pH
TA
CH
CYA

We are not like a lot of pools sites that just guess what is wrong with your pool.. We need facts to help us decide if there are any issues..

Thanks for posting,

Jim R.

 

[Mackhatter]

Mack,

Plaster dust should have been long gone by now...

Using the kit you have, please post a full set of current test data as follows..

FC
CC
pH
TA
CH
CYA

We are not like a lot of pools sites that just guess what is wrong with your pool.. We need facts to help us decide if there are any issues..

Thanks for posting,

Jim R.

Thanks Jim- here are the latest results just now:

FC. 3-6
CC 1-2
PH. 7.3
TA. 200
CH. 200
CYA <30

Thanks for your help!

Bill

 

[justinc]

Your free chlorine is not too terribly off but you will know a more exact number rather than a range once you get the FAS-DPD test in. The problem is your combined chlorine is high enough to warrant SLAMing the pool (what you know as "shocking). You should bring your chlorine level up over 10ppm with liquid bleach (use Pool Math) to calculate quantity needed. Maintain at 10ppm until you have 0.5ppm or less CC and overnight free chlorine loss of less than 1ppm. Your total alkalinity is high so you will have to aerate to raise pH and then lower with acid to reduce both pH and alkalinity. You may be able to get away using calcium hypochlorite shock for the next few weeks or during your slam because it will add both chlorine and calcium to your water. I would consider using cal hypo until your calcium hardness gets a little closer to 250 and then switch back to liquid chlorine/bleach.

 

[Mackhatter]

I’m into the process. As you can see, the water clarity is great. My chlorine test kit arrives Monday so i’ll Have a better idea of accurate readings.I have a large 1300 gph air pump going through 8 air stones for aeration, and am slowly starting to see the TA coming down. Patience is the key word.

 

[mknauss]

Will take your word for it on the clarity. From your picture looks pretty cloudy to me -- but must be the lighting.

Can you see head or tails on a quarter in the deep end?

 

[Mackhatter]

Yeah, it’s the lighting. The coin test, that’s a good idea. But my “deep end” is only about 5.5 feet. Of cours, you’re assuming my eyes can still work that well?.

I’ll try that tonight when I take my water measurements and turn the aerator off to let things settle down. Right now, my main task is bringing the TA down and then it will be a lot easier balancing everything out

 

[Rollercoastr]

I think we're looking right at the aerator, which complicates it. The light hitting it in the upper right corner shows clarity...?

But hey indoor pool guy, good to see another here. Welcome to TFP!

Couple of other notes: your CH is a little low. Plan to give that a bump?

Tablets are a trigger here because they cause so many people so many problems, but they can also be a solution. You will see attrition in your CYA levels over time, so you can work that to your advantage by carefully monitored usage of tablets. A small container lasts me a long time, but they also save me the trouble of adding CYA granules and worrying about FC (and actually pH) levels in times that I'm away from the pool.

 

[Mackhatter]

Thanks! Yep, working on multiple fronts with the chemistry. Another 30# of Calcium Chloride should get my CH to 400. My SLAM is just about over- just waiting on my CL test kit to arrive tomorrow. My aeration pump just decided to die on me, so I have to stop my TA reduction process temporarily.

And yes, right now my CYA is next to nothing, so once my SLAM is over, that will get my attention also.

Us indoor guys are few and far between, but up here, it makes sense, plus happy wife, you know the rest.

Thanks for the welcome and the tip.

Bill

 

[Mackhatter]

A quick update and a Big Thanks to all the expert help, and especially onBalance for his diagnosis of my plaster. It turns out I was not as paranoid as I thought, and all the issues I was having were poor plastering from the PB. So the journey begins with the first meeting with the PB today. But for now, one picture...