Pool re-plastered two weeks ago--brown stains everywhere

svott

0
May 25, 2010
4
Dallas, TX
Hi everyone,

I recently bought a house with a 13 year-old pool with no previous personal experience maintaining such a thing. The original surface was wearing out (chipping, stained) so I decided to get it re-plastered. After interviewing several contractors I decided to go with one of the more expensive ones with the idea that I would get "better service." Part of the contract was that he would complete the start-up process including brushing, balancing chemicals, and adding the salt when ready.

The new plaster was applied on 22-May and municipal water added same day. The contractor came back out two days later to brush and add muriatic acid. Repeat once the following day. Then on 27-May he came back to add soda ash and start the pump. After that he has basically disappeared: no visits and no answer to my phone calls. This wouldn't have been so bad except now I'm seeing brown stains developing all over the new plaster. The water, however, is crystal clear and has no discernible odor.

I didn't bother to understand much of this process until recently because I was assured by the contractor everything would be taken care of. He gave me no instructions. Now I feel like I was duped and that I need to take matters in to my own hands. I just read the pool school article "Start-up New Plaster" on this website and realized the surface has not been brushed nearly enough.

The test strips I have show no measurable chlorine or stabilizer in the water. The pH, total alkalinity, and total hardness are in the "OK" range as far as I can tell. There is no salt added yet.

I've tried brushing the brown stains firmly with a nylon brush to no effect. I got some vitamin C tablets and rubbed them into stained areas and nothing happened. I can't be sure what the contractor may have added to the water in terms of sequestrants, so I have to assume nothing.

The pump has been running continuously for the last 12 days.

Does anyone know what these brown stains might be, and how I can get rid of them ? Is it too early to shock the pool to see if that would help (maybe the stains are organic) ? I'm thinking about rubbing a chlorine puck on some stains to test. Bad idea ? What else should I be doing at this time ?

I just ordered the TF-100 test kit so I should be able to post numbers when that arrives.

Thanks for any advice !!
 
Welcome to TFP!

What chemicals have you been adding? Typically a new plaster startup uses trichlor tablets, perhaps in a tablet feeder, and acid regularly.

It would be a huge help to have a full set of water test results that you can trust. When do you expect to get the TF-100?
 
Thanks for the replies.

PoolGuyNJ: I didn't get any fancy brand-name finish, just regular plaster cement with Metamax and Superblue quartz mixed in (as they described it). When I said municipal water I just wanted to clarify that it was city water as opposed to well water, since I've been reading several posts on this forum about brown stains caused by well water. I filled it with my garden hose over the course of about a day.

JasonLion: I haven't added anything at all to the water. With the new plaster I was not sure what would be appropriate or safe. I know that the contractor added a lot of muriatic acid for the first three days, and then soda ash after that to balance out the pH. He told me he was also going to add ScaleTec, but I am unsure if it was ever added. Should I start using trichlor tablets ? My test kit shipped out this morning (fast service!). I would expect it to arrive sometime this week.

Should I add a sequestering agent to the water, even though the vitamin C pills had no effect ? If so, do you recommend Jack's Blue Stuff ? Or should I add Jack's Purple Stuff, knowing that I'll be adding salt to the water soon for the SWG ?

Thanks !
 
For a new plaster startup you typically add some sequestrant "just in case" since metal stains on fresh plaster can become embedded in the plaster and impossible to remove. Jack's Magic The Blue Stuff is an excellent choice, since it is optimized for new plaster startups.

The National Plasterers Council recommends waiting 48 hours before adding chlorine. After that, trichlor is a good choice if you have a tablet feeder or are running the pump 24x7 and put the tablets in the skimmer. Trichlor adds both chlorine and CYA slowly and gently, avoiding possible issues, and also helps lower the PH.

It is important to keep close track of the PH after a fresh plaster startup. After a couple of days the PH will start going up very quickly, and you need to keep the PH under control or you can get calcium scaling.

You should wait till 30 days after the plaster was applied before adding salt.

A good place to check for fresh plaster procedures is the National Plasterers Council startup card, which covers lots of stuff that can help the startup go well.
 
Followup: I finally was able to speak to the contractor that did the resurfacing job. He came over and added 12 gallons of muriatic acid and a bottle of Jack's Blue to the water, turned off the equipment, and circulated the water with his own submersible pump for 3 days. After just 12 hours or so the brown stains were either gone or replaced with a gray dust that was easily wiped off the surface. He then returned and added soda ash and restarted the equipment.

Okay, so far so good. Except now every time I sweep the new plaster surface I get plumes of dust that leave the water cloudy for a day or so. I'm still running the pump 24 hours/day but I'm not sure if the filtering is effective or this dust is just setting back on the bottom for me to sweep into the water each day. Might that pH level have caused damage to the 3 week-old surface ?

Also I got my TF-100 test kit in the mail. I ran the tests and have these numbers:
FC 4
pH 7.2
TA 70
CH 800
CYA 20
CSI -0.03

The calcium level is alarmingly high. To make sure I'm not making a mistake I took a water sample to Leslie's and they got a CH reading of 600. I then tested my fill water and found the CH to be 220. Where might this high calcium concentration have come from ? I'm only adding bleach to the water to chlorinate (not cal-hypo).

(I know my CYA is too low, but I didn't want to add too much in case you guys tell me I have to drain water in order to reduce the CH).

Should I really be concerned about the high CH ? The pool calculator give me a CSI of -0.03, which as far as I understand is about as good as I could expect. If I just manage the pH carefully is the CH a non-issue ?

Thanks very much for the advice.
 
The high CH level came from all of the acid they added. It dissolved plaster out of the pool surface and into the water. You can manage the high CH level by keeping the PH and TA low, but eventually you will need to replace water.
 
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