Calcium problem or not???

[georgiaboy]

I have a 16x32 gunite pool, 6.5ft deep end, 6 years old and converted from chlorine to pentair salt generator 2 years ago. I originally questioned pool company about some rust colored stains that appeared over last year that looked like a hair bobby-pin had been left on bottom and rusted, but there is hasn't been anything dropped in pool to rust. My pool is crystal clear, I have had some varying darker and lighter areas in deep end over the last few years. Now I have some in 3 of the rust looking stains different places in my pool about 2 inches long each and some of them are in a V pattern with each side about 1-2 inches. Pool installer hasn't seen them in person, I did show photos and said it was either black algae or deposits from calcium/minerals and I needed to drop water level and replace to lower calcium. Calcium was 350 mid week and I drained it 5 inches and refilled as was instructed now level is 380 today. They told me to drop/replace water again today and recheck Monday. Every other level checked was within normal limits except calcium. 6 years and I've never been told to lower water and replace, not convinced this will help and wonder if my well water my be raising it. Told me to try stain free on the rust looking spots, haven't done that yet. Any suggestions/ comments would be greatly apprecitated. Let me know if there is any other info that may be needed about my pool, wish there was a way to post images of the stain to see what people think they are.

[PoolDoc]

They are making a fairly typical pool store pitch: "Try to solve your problem with this expensive chemical/process, and if that doesn't work, try this other expensive chemical process". Since calcium doesn't cause rust colored stains, I'm guessing they'll get into your wallet pretty deep, before the problem gets fixed!

Instead, do this:

1. Learn to test your pool correctly, with a good test kit . . . and then tell us the results. (Links below!)
2. Take some vitamin C tablets and put them ON some stained areas, and leave them there. If the stain is lightened after 10 - 30 minutes -- it's an iron stain.
3. Read the muriatic acid page, linked in my signature, and lower your pH to 7.0 - 7.2, which will temporarily reduce any tendency to stain.
4. BUT, if the pH is below 7.0 now, get 20 Mule Team borax and use it to RAISE your pH to 7.0 or above.

+ Get a cheap OTO (yellow drops) / phenol test kit, or if available at YOUR Walmart (check availability), 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 )

One caution for the 2012 season: Amazon does not stock the kits directly. So when buying at Amazon, Amato is our current preferred seller. However, they often don't list enough stock to last the whole day, so try order mid-morning. You should expect a delivered cost under $60 for the K2006A and under $95 for the K2006C. If you can't find that, wait a day.

+ Here are links to the kits we recommend:

HTH 6-Way Test Kit @ Walmart
Taylor K2006A (3/4 oz bottles) @ Amazon
Taylor K2006C (2 oz bottles) @ Amazon

[georgiaboy]

Thanks, I will purchase a 6-way kit this week and post up results. I have a ph and chlorine test kit that I use weekly, today ph is just below 7.2 color and my chlorine was high 2's. I lowered setting just a little on generator, I had turned it up some after adding 5 inches of water to compensate for the dilution.