Stain on Pool Bottom [Archive]

danas831

06-11-2012, 03:00 PM

Hi, first wanted to say thank you for providing such a great forum! I bought a home with an inground pool last year. I took it over in August so I didn't do any testing with the water because it stayed clear until I closed it. After reading through your suggestions I now know that was a mistake.
Anyway, I opened the pool and got it all clear within a week but I didn't realize the ph was low (about 6.0) until I took the water for testing. I had the pool sparkling clear with no stains one day and then the next day it was sparkling clean with these tannish/orangish stains at the bottom of the pool (mostly in the deep end).
I have an inground vinyl pool 3-12 ft deep with approx. 28000 gallons. My levels are as follows:
FC - 8.35, TC- 8.35, CC- 0, ph- 7.6, TH- 231, TA- 162, CYA- 56, Copper- .82, TDS- 1340. I have done a treatment for the copper with 11oz of les iron and after retesting with 32oz of jacksmagic blue but the level is still high.
I just bought a jack's magic stain test kit but after reading it says to adjust my levels and before I bother doing any of that I wanted to look for suggestions here first. I foolishly ran the heater to the pool while the PH was low (not knowing that it was an issue) and I believe that is what is contributing to the copper as my heater now needs service.
Thanks in advance for your help!

PoolDoc

06-12-2012, 05:37 PM

Hi Dana;

Do all these things:
Lower the pH back near 7.0, not below.
Use muriatic acid to LOWER pH (instruction link in my signature); use borax to RAISE your pH.
Do NOT trust the pool store testing (BioGuard?); get a testkit (see below)
Drop some vitamin C tablets on the stains, and see if it changes them.
Unless you have algae, let your chlorine drop into the 1 - 3 ppm range.
Buy (or order) some polyquat (read www.poolsolutions.com/polyquat.html -- see order link below)
Adjust your pool inlets so that none of them directs water against your pool's surface.
Fill out the Pool Chart.

I've cut and pasted relevant paragraphs from an FAQ the PF Support Team is working on.

Ben

+ Get a cheap OTO (yellow drops) / phenol test kit, or if available at YOUR Walmart (check availability (http://www.walmart.com/ip/HTH-6-Way-Test-Kit/17043668)), get the HTH 6-way DROPS test kit, which is compatible with the Taylor K2006. Test the pool as soon and you can, and post the results. If you get the 6-way kit, ALSO test the water you FILL the pool with, especially if it's a well, and post THOSE results as well. (The HTH is the best available kit you're likely to find locally, but it's not the K-2006. It can only provide rough measurements chlorine levels above 5 ppm, and it measures "TOTAL" hardness, rather than "CALCIUM" hardness, which is not ideal.)

+ Having a good test kit makes pool care easier for EVERYONE. A good test kit means a kit that can test chlorine from 0 - 25 ppm, pH, alkalinity, calcium hardness, and stabilizer with reasonable accuracy. Test strips (AKA 'guess-strips' ) do NOT meet this standard. Some pool store testing is accurate; most is not. The ONLY way you'll know whether your pool store is accurate or bogus, is by testing accurately your own self. On the other hand, pool store 'computer' dosing recommendations are NEVER trustworthy -- ignore them. They are designed to sell more chemicals than you need, and WILL cause many pool problems.

+ We recommend the Taylor K-2006 test kit, which meets the requirements above, for many reasons. The HTH 6-way drops kit is a great starter kit, and is compatible with the K2006 (it's made by Taylor). There are a few alternatives; for example Lamotte makes an FAS-DPD kit that's OK -- but it costs 3x as much. But, we're not aware of any test that is better, and since we are all familiar with the K-2006 (and can help you with it) we recommend it exclusively ( Test kit info page (http://www.poolforum.com/pf2/showthread.php?16551) )

+ It's much easier to answer your questions, when we have the details about your pool in one place. We often 'waste' the first few posts back and forth collecting information. So, please complete our new Pool Chart form -- it takes about 30 seconds, but will save much more than that.

Pool Chart Entry Form (http://goo.gl/cNPUO)
Pool Chart Results (http://goo.gl/PXaLu)

+ Chlorine is the strongest algaecide you can buy . . . but occasionally, you may need a different one. Almost the only alternative algaecide we recommend is polyquat -- poly [oxyethylene (dimethyliminio) ethylene (dimethyliminio) ethylene dichloride] . This product is a GOOD clarifier and a moderately good algaecide, with almost no bad side effects. We often recommend it for use when you are going on vacation, or when you need to lower your chlorine, to prevent remove stains. It has become quite difficult to purchase locally at the normal full strength 60% concentration. If you find it locally, at a 60% concentration, that's fine. But be SURE to check the chemical name. If you need to buy it online, here's an Amazon link:
Kem-Tek 311-6 Pool and Spa 60-Percent Concentrated Algaecide, 1 Quart (http://www.amazon.com/exec/obidos/ASIN/B0030BEI0Y/poolbooks)