how do I perform an acid startup on light grey plaster

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carlos31

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Oct 18, 2007
104
Central Texas
I want to perform an acid start on my upcoming plaster installation. I will have an Intelliflow 4x160, Quad DE100, no heater, BBB using Liquidator and pool will be approximately 45K gallons. I found these instructions here on POOL SCHOOL and had a couple questions.

1. Fill the pool or spa.

2. Add sequestrant (any recommended brand and what volume of sequestrant?)

3. Add 4 gallons muriatic acid per 10000 gallons. This will dissolve the plaster dust without brushing.

4. Brush daily but don't vacuum or add chlorine until plaster dust is gone. For dark plaster only brush lighter colored or white areas. (only once a day or the more the better?)

5. When all plaster dust is gone neutralize the acid with soda ash by using a base demand test, wait 24 hours and repeat if needed. (if I use the TF-100 how do I do a base demand test?)

6. Turn on circulation system when pH is 7.2 or above, clean filter when the pressure increases 10 psi, add sanitizer in small amounts until desired level is obtained. (doesn't the water need to be circulated the entire time perhaps bypassing the filter or using a sump pump?)

thanks
 
An acid start up should be done by your plasterer or builder, it requires some equipment, knowledge, and testing not generally available to a homeowner. It's not something you should attempt yourself. Talk to your builder or plasterer about it.
For example, filling the pool or spa requires more than just throwing a hose in! Often multiple hoses are used to fill as quickly as possible and special precautions need to be taken not to mar the new plaster with either the hoses or the water going in!
Plaster startup is the builders or plasterer's responsibility. No matter what method they recommend follow their instructions.
(And to answer your question, you cannot do a base demand test with the TF100. You would need a different test kit.)
 
I checked with my plaster company and they do not perform start-ups. I am the builder so it is up to me. The plaster company will provide the instructions from the National Plasterer's Council.

I saw it done once but the plaster guy questioned that particular job since the start-up guy used a sump pump to circulate water instead of the main pump. (I believe this was because there was no bypass for the heater and the acid is bad for the heater) He said the sump pump often leaves a ring which must be polished out later by a diver. So, I doubt I will be hiring that guy. I have gotten this far with no previous experience, so I am going to end up attempting this as well. If anyone has done there own acid start-up, I would appreciate any tips or tricks you may have.
 
This guide from United Chemical might be useful to you. If I am not mistaken they are the ones who developed the acid startup procedure. (Actually, Jock Hamilton, former head of United chemical until his death.)
http://www.swimpool.com/pdf/UCC_plaster.pdf
realize that this guide uses all united chemicals products but generic products can be substituted. (Easy pH is just soda ash).
You will need a Taylor K-2006 or K-2005 for the needed base demand test. Teh TF100 does not include acid and base demand tests since they are not that useful in normal pool maintenance.
 
The United Chemical start-up instructions seem to be the best available. I called the company and a tech answered a few questions for me. First, he clarified that I should chlorinate with a floating trichlor dispenser since my climate is still warm (Austin, Texas). Second, he stated that brushing the pool is sufficient to keep the muratic acid in suspension with the water. My plaster company thinks the water should be circulated immediately via the main pump or sump pumps in the pool since the muratic acid is heavier than water and they have seen this cause damage to plaster on the bottom of pools.

I will be using BBB but I need to raise CYA anyway, so using the tablets doesn't sound bad at first, but I understand the chlorine will reduce the effectiveness of the sequestrant and chelator. Also, it looks like it would take 46 three inch (7 ounce) tablets to get to 30 CYA on a 45K gallon pool. I imagine that will take a while via a floating dispenser.

Question: Can you advise on any telltale sign or test that would indicate when I should introduce the trichlor to the water? Should I wait a couple days until the sequestrant and chelator has done its work?

Question: Do you think the plaster company or chemical company is correct with regard to brushing versus constant circulation to prevent the settling of muratic acid on the pool bottom? Does muratic acid come out of suspension unless circulated? The dose required is 4 gallons/10K gallons water, so I will be adding 18 gallons of muratic acid.

Question: Can you recommend a particular chelating agent? I assume I want one that favors calcium. There is no metal in the fill water according to pool store tests but I understand this to be questionable based on some of the posts I have read while trying to brain-up for this startup. (I don't believe I can get the United Chemical chelating agent because its only sold wholesale to SCP and SPP and I don't have a business account with them.)

thanks for any advice
 
Carlos,

I am at 36 days since fill. My PB did an acid startup on my Pebble Fina plaster. Immediately after finishing (Tuesday about 4:15PM) the plaster guys taped some plastic bags that had the ends cut off to three hoses and dropped them all the way to the bottom of my deep end. It looked like the plastic acted like a diffuser. The PB told me to brush as soon as it's full at least three times a day for 10 days. They said that I couldn't brush too much. You should start brushing at the shallow end and work towards the main drains. It seems like the brushing mostly stirs up the plaster dust so it can make it's way to the filter.

Pool finished filling at 4:45PM on Wednesday. On Thurdays they came by during the morning and added acid and then turned on the pump at about 2500RPM. I also have the 4X160. Sorry but I was at work so I can't tell you how much acid they put in. On Monday they neutralized the acid. I believe they added a bit of chlorine at this time also since we were cleared to use the pool at this point.

When I first got in I was worried that something was wrong because the bottom was very slippery. It turned out that the slippery feeling was caused by plaster dust. At the end of the 10 days the plaster felt and looked great.

Good Luck and show us some pics. 45K sounds like quite a pool.
 
cobra46,

So it sounds like a 4 day acid start-up with the pump running and the filter engaged (no bypass). All the sources I can find seem to indicate an acid ratio of 1 gallon per 2500 gallons of water.

What type of filter do you have? I have the Quad DE100. I guess this means the pool builder didn't believe the acid would harm either the 4x160 (which I wouldn't think it would) or the filter. In my case I can't use the filter until I add DE but I probably should not add DE via a skimmer until the acid start-up is complete. I also don't know what effect the acid may have on the Quad DE "cartridges", so I will bypass the filter if using the main pump for circulation.

I have been neglecting the pics, I will resolve that shortly.
 
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