Pink "Stuff"

[djg9100]

First time in 18 years have a small amount of pink growth in a few places in corners and walls. 30,000 gunite pool that is due for resurfacing. Read that this is a bacteria an not algae. Chlorine pool.Calcium Hypochlorite. Trichlor tabs.

What is best solution for this?

Thanks

[PoolDoc]

What is best solution for this?

1. PH in a non-damaging range ( 7 - 8 ).

2. Chlorine ppm = 20% of CYA (stabilizer) level or more. (ie, if your CYA = 70, your chlorine should be 14 or HIGHER!)

3. Brushing.

4. Once you've got things under control low phosphates (<150 ppm) and high borates (> 60 ppm) will help prevent recurrences. But they ONLY help. You've still got to manage the chlorine and cya levels. But with a rough pool finish, managing these two levels well help, and shouldn't be hard or expensive unless your pool leaks.


So:

+ Read http://pool9.net/cl-cya/
+ Order a K2006 test kit. http://pool9.net//
+ Meanwhile, get a CYA test result, and dose with PLAIN 8% househould bleach as needed. On a 30k gallon pool, each gallon of 8% bleach will add about 3 ppm of chlorine.

[djg9100]

Thanks for the info. Got BBB info and ordered test kit. Also using phos-free weekly. Phosphates typically 100 or less.
Thanks and will advise of test results once I get the kit.

Don

[PoolDoc]

This product
CLOROX Pool Phosphate Remover 1 Quart removes 2,000 ppb (2 ppm) of PO4 from 10,000 gallons. That's usually less than 1/2 what Phos-free does costs, per unit of phosphate removed. It seems to be slow acting, so if you test immediately, you won't see much reduction.


WRONG: Turns out the Clorox phosphate remover is a seriously bad deal. A quart of the Kem-Tek predecessor product was labeled as removing 2 ppm PO4 from 10K gallons; the Clorox product is virtually the same price, but only removes 0.75 ppm from 10K gallons.

That means the Clorox product is actually 267% more expensive!


The Orenda PR-10000 product removes 5x that (10 ppm per 10k gal) per quart, so if you purchase it for less than $70/quart it's even cheaper. But you have to be careful with it, or it will cloud your pool.

[djg9100]

Ok. Got test kit and tested CYA. Based on the test my CYA is about 130. The black dot disappeared and the water level is below the letters CYA on the test bottle and based on scale it appears to be in the 130-150 range.

FC = 2.4 [12 drops x .2]
CC = 0.40 [2 drops x .2]

Additional tests
ph = 7.4
ALK = 170
Ch = 460

.

[PoolDoc]

You need to take your chlorine level to 30 ppm (20% of your CYA level). You can still swim with chlorine at 20%; I have a 200,000 gal country club pool that's been doing just that for the last couple of days -- no complaints, no problem, no one even notices.

[djg9100]

I purchased the Clorox Pool and Spa Phosphate remover quart bottle for $17 on amazon. Per chart to remove 250 ppb from 10k pool requires 1/2 the bottle. [$8.50]. Not sure how that compares to the other products. Have been using Phos-free which is about 50-60 bucks per 3 quart jug.

[PoolDoc]

It compares badly.

I got 20 quarts yesterday and was massively disappointed to see the dose ratings. I'd assumed that they were the same as the Kem-Tek product, but they are not. I've got calls in at KIK (makes Kem-Tek and the Clorox brand products) to see what's going on, but haven't heard back yet.