New user looking for help with scale

[motion guru]

We put our pool in and started it up in the spring of 2005. It is a Hydraazo finish 18 x 36 at 9 feet at the deepest end. We figure it is about 27,000 gallons and we set up from the beginning with a Salt Water Generator.

Thus far it has been a great pool that has suddenly experienced a significant amount of scaling - hoping to find some assistance here.

[Watermom]

Post a complete set of current water testing results taken with a drops-based kit. The kit we recommend is the Taylor K2006 or 2006C (better buy). Not available locally; you can get it here: http://pool9.net/tk/ (Until your registration is complete, you'll have to log out first to be able to see the rest of the forum, so copy that link and paste it in a browser window after you log out.)

In the meantime, you can pick up a HTH 6-Way kit at Walmart (not the 6-Way test strips) and use that to check your readings.

Welcome to the Pool Forum!

[motion guru]

I researched this topic quite a bit and have already started taking steps to get the calcium scaling under control, but I am treading into territory where I have no experience and am not altogether confident that I am doing the right thing.

I have a Taylor K-2005 Test kit, I see you recommend the K-2006 which I can get when I need more reagents -
I balanced the pool chemicals in Sept when we shut it down, pH was 7.4 and everything looked good. When I opened up the pool cover to check on it in March - I got the following readings:

pH 8.0 (as high as the scale goes) It took 4 drops of reagent # 5 to get it down to 7.6
FC 0
TA 100
CH 180
CYA 0
Temp 42F

I also measured phosphates and they were through the roof - (above 1000 ppm), Salt 3000

I noted way more scale than when we had closed it over 80% of the surfaces are affected, the steps were rough like 36 grit and at that time I scraped some off and it bubbled furiously in vinegar and also in muratic acid. The crystals look clear when in the water and white when out of the water.

I added acid and then decided to set the pump to run 6 hours a day and checked it weekly through the month of March - I kept the pH between 7.4 and 7.8 by adding acid regularly (went through 4 gallons of acid in March)

The scale was not improving so I decided to pull the pH down to 7.2 and keep it there as best I could, I added 64 oz of Purple Stuff and this seemed to help over the next two weeks. The scale was still very hard, but it did come off of all the tile and it became smooth. The scale stubbornly clung to the hydraazo.

I called Jacks and they suggested Solution #2 and directed me to some instructions - I waited a while to see if I could get things to improve without spending the money on this solution - but with no improvement by the end of April - I ordered 4 qrts of purple stuff and enough solution #2 to dose the pool.

I put the Solution #2 in according to the instructions 1 week ago. I have seen no additional improvement yet.

I have been keeping tabs on the pool, today's readings are:

(I started using chlorine tablets as I re-plumbed the heater and salt cell out of the circuit before dosing with Solution #2)

FC 1
pH < 7.0 according to the Taylor test, it is <6.8 according to the test strips I bought
TA 40
CH 250
CYA 0
Temp 72F

Phosphates still > 1000 ppm and Salt 2700

So far, the most effective means for getting the scale off is to use a left over tool tile and just scrape it off. I was hoping that it would go back into solution with a little less work . . . perhaps I am being too impatient?

Has anyone else used this treatment with this kind of scale and gotten good results?

[PoolDoc]

Please look at the 'sand algae' page, and see if this is what you have experienced: http://pool9.net/algae-s/

. . . membership upgraded.

[motion guru]

Yikes - that is much worse than what we are experiencing. We don't have any green, no slime and the water is clear. I'll try to get a decent photo and post.

[PoolDoc]

The algae deposits the calcium; the pictures showing the white sand-like particles are what remains after the algae is gone.