What to balance first pH or TA, iron removal in progress

[nire878]

Hello -

I just filled my new small, vinyl liner pool, and unfortunately made a good size error. The pool was mostly filled with surface water, quality (per pool store):
FC, CC, CYA: 0 ppm
TA: 34 ppm
TH: 17 ppm
pH: 7.6
iron: 0.1 ppm

I had a few more inches to go, and I thought "I have hard water, I will just use the hose to top it off!" Well in addition to slightly harder water, now I have a lovely shade of orange in the pool (per Taylor 2006):

FC: 4 ppm
CYA: 35 ppm
TA: 50 ppm
TH:50 ppm
pH: 7.0
iron:?? - I will have to bring a sample to a pool store

I am using the you tube 5 gallon pail pillow stuffing method for iron removal and it seems to be slowly working, but in the mean time, I want to adjust the pH and TA. Per pool math, adding baking soda for TA will also have an impact on pH, so should I adjust TA a little first and then adjust the pH? Start with the pH (Borax) and then adjust TA, or not do anything while my iron removal efforts are going on? I thought a higher pH was more likely to bring the iron out of solution and into a particulate form, so I wanted to get into a 7.4 - 7.6 range.

Thanks so any comments or suggestions!

 

[Mr Bruce]

If you could point your returns up to ripple the water or run a robot or otherwise aerate the water to raise pH that would be best.

I wouldn't bother raising TA yet, keep an eye on pH and see what it does for a week or so.

To answer your question directly, pH first, TA last (after everything else.)

e: You do want to keep pH lowish with metals in the water. I would really hold off any chemical additions to raise it. Somewhere around 7.2 would probably be best.

 

[Texas Splash]

Welcome to TFP! You're correct in that the elevated pH "should" cause the iron to precipitate more. Just be careful about it effecting or staining any other areas. That's tricky territory. If you do take water to get re-tested for iron, make sure to grab a clean sample from the source and not the pool where chlorine has already been added. Once you're done with 5-gal filtering and are ready to adjust levels, I'd keep the pH in that 7.2 zone. I wouldn't worry too much about TA at all at this point. Don't forget to review the Pool School - Metals in the Water and Metal Stains page and let us know if you have anymore questions.

Nice to have you with us.

 

[nire878]

Thanks so much. I have adjusted pH just a bit using the borax and will not worry about TA for now. I am really pleased with the iron removal, the water has gone from Orange to kinda brown green to greenish blue tonight. I think two more days and I will be able to call it quits, and can then really get the water balanced. Thanks again.