My new plaster pool is COVERED in green stain..

[PoolDoc]

Good points, Waterbear.

PoolDoc

[waterbear]

Good points, Waterbear.

PoolDoc

thanks!

[hausfrau]

You are all so very helpful. Update: My husband drained down the spa and squired a solution of meriatic acid (10%) and water. Boom. Stain completely gone. A neighbor was able to gingerly rub at a dark smear on the side of the pool and he actually was able to remove the stain. This was using a stainless brush which I am not a fan of and have not used. So, this being said, my local pool store suggested we brush the pool (used nylon brush) and put in a solution called Supercide (algea destroyer and stain remover). Honestly, I don't see much difference. Algea may look a little lighter in some areas. Sometimes your eyes play tricks.

Here's the readout. 14000 gallon pool. temp 85 degrees, algecide level 0, Protector 28 N, total solids 1700, saturation index -0.4, free chlorine 8.0, total chlorine 8.0, alkalinity 45, calcium hardness 220, ph 7.4, stabilizer 100. They suggested low alkalinity and had me buy equalizer. Then, muriatic acid. This was tested on Friday of last week. it is now Monday. I will probably get it tested again tonight as I will be near the pool store.

[hausfrau]

The chlorine test I am using is a home strip that you dip into the water. I don't like it alot as the reading won't tell you how high the chlorine is...just that it is too high! it will be high right now because of last nights Supercide treatment...I turned off the chlorinator until it seems to level off.

Initially, our pool installer had the chlorine cranked all the way and I did not realize I was supposed to turn it down after a few days. Now that I know how to adjust the chlorine flow, I can better adjust that. Man, this is a pain. I never should have put in a pool ;0

[mbar]

You have algae, and the only way to get rid of it is by using high levels of chlorine until the chlorine holds within 1ppm overnight. With a cya of 100 you need a minimum of 8ppms, and to take the pool up to shock levels you will have to take your chlorine level up to 25ppms and keep it there testing every couple of hours to get it back up to 25. You may also want to do a partial drain and refill to get your cya between 30 and 50. You are wasting money on all the chemicals the pool store is selling you to kill algae that will die with high levels of plain old bleach . I would be very leery of the chlorine tabs with specs in them. Make sure they don't contain copper. You also don't want to use the chlorine tabs that are trichlor as they will raise your cya even more. You should take a look at the chlorine forums and the algae forums - you will see that good old fashioned bleach really does work. The best suggestion I have for you is to get a good test kit so you can test your own water and learn how to take care of your pool yourself and not be at the mercy of pool stores. Do a lot of reading on this site, and ask any questions you have. Everyone here loves to help

[hausfrau]

You are so nice.

I have actually asked about a more high tech kit for testing my water and was told there isn't really anything better than the strips I am using. Hmm...a plot here? I do not want to be at the mercy of the pool stores...I am a nice calm person, but I am getting rather riled up as each time I go in, I get a different opinion.. Iwas wondering...should I have my well water tested-the water that the pool is hooked up to?

I will take your suggestion...and thank you for it. I am going to take a pool class that Self-Chem offers...but will take some of it with a grain of salt (no pun intended) as they probably want us to be dependent on their chemicals! I am also brushing the plaster more right now in hopes that it will inhibit the growth too. We are having lots of storms now (near Austin, TX) so I am sure this will throw everything out of wack too.

Please wish me luck! I'll keep ya'll posted on my pool nightmare!

[waterbear]

You are so nice.

I have actually asked about a more high tech kit for testing my water and was told there isn't really anything better than the strips I am using. Hmm...a plot here?

As someone who has worked in pool stores I can tell you that the answer is probably yes. We did not carry decent test kits (except for the K-2005 we stocked in units of 1 for the condo associations) so people would come to us for water testing and we could sell them a lot of stuff!
As far as test kits, get yourself a Taylor K-2006 (not the K-2005). It will save you a lot of time and money in the long haul!
You might have to order it online. Here is a link for Amazon:
http://www.poolforum.com/pf2/showthread.php?t=10006
While this is not the only place you can get it you will be supporting Pool Forum by ordering from this link and help keep it going.

[hausfrau]

Just for the heck of it, I had our well water tested to check on metal in the water. it came back very low for copper...0.2. So yes, algea. Now, to get a decent test kit (as suggested on this site) and buy some bleach...will keep ya'll posted!

[hausfrau]

Thanks for the good advice!

Muriatic acid seems to have done the trick in our spa. We turned the spa off and added a muriatic to the water. Let it sit for an hour. It really cleaned it up. The concentration would have been about .2% for total volume.

A few questions:

1. What is the maximum concentration of mutriatic acid that can be safely used in a plaster pool? (14400 gal)

2. Can the PH be lowered a significant amount for a period of time then raised to normal levels without potential damage to the plaster?

3. Should the DE in the filter be changed or backwashed to eliminate any residual algea?

4. As an aside, to eliminate the possibility of metal staining, will muriatic acid also remove Cu or other metals from the surface of the pool?

Again thanks for the help. Big learning curve for us on this!

[hausfrau]

Did all of that. Honestly, we have tried it all. Still there...a little worse. Is it possible that minerals or something is leaching from the gunite that can cause stains which are almost impossible to remove? The pool's gunite cured during heavy pollen season. The pool is under trees. If the plaster folks did not wash out all of the pollen properly..could this be causing a problem?