newbie back. finally have new filter running. need a some guidence with test levels.

[rnjng]

OK, I completely connected our new filter yesterday, after about a month with no filter. 24' round ag 13500ish gallons. Last night I shocked with bleach. This morning I tested and the numbers were.(hth 5way drop kit)

CL/BR-way high, over the 5/10 on the vial
PH- lower than 6.8
alk- 40
cya-80-90
hardness, no change in water color




This evening, the readings were
cl/br- 5/10
ph- lower than 6.8
alk dropped to 30
cya no change 80-90
hardness no change in water color


After the evening reading I added about 1 1/2 pounds on borax and tested 3 1/2 hrs later with these results.


CL/BR 5/10
ph just lower than 6.8

Whats your thoughts, am I on the right track??? Can I keep adding borax in small amounts to get to the right level?

[chem geek]

Whats your thoughts, am I on the right track??? Can I keep adding borax in small amounts to get to the right level?

Your alkalinity is low as is your pH, so you could attack both at once by adding Soda Ash (Sodium Carbonate) or you can add both Borax and Baking Soda (bicarbonate of soda). Probably the safer and easier thing to do is to keep adding Borax to get your pH to the right level first and then add Baking Soda (bicarbonate of soda) to bring up your alkalinity (TA) to at least 80, then follow this with a final touch-up of Muriatic Acid (if needed, since the Baking Soda slightly increases pH) to get to your desired pH (7.4?). Or you can go back and forth between your Borax and Baking Soda (only start adding Baking Soda after you get to a reasonable pH of at least 7.2) to try to get to your levels without any overshoot -- it's no big deal if you do and need to correct it, it's just a matter of taste.

You show no calcium hardness (CH) at all. Do you have a vinyl pool or a plaster/gunite with grout pool? If you have a vinyl pool with no tiling that has grout, then you won't need the calcium, but if you have a plaster... pool, then you will.

Richard

[rnjng]

sorry, it is a vynal pool. I just added 8oz of borax. will test in the morning. Thanks for the reply.!!!!!!!

[chem geek]

sorry, it is a vynal pool. I just added 8oz of borax. will test in the morning. Thanks for the reply.!!!!!!!

I'm sorry I don't have the borax calculations in my spreadsheet yet, otherwise I could tell you how much to add. So, keep with the incremental changes and note how much affect each change makes as a guideline.

Good luck. You are on the right track!

[rnjng]

How much baking soda would I need to get to a target of 80-90ppm? I used the bleach calc and it said to add 11lbs??? I can just dump it in front of the return. AG 13570 gal vynil.

[chem geek]

How much baking soda would I need to get to a target of 80-90ppm? I used the bleach calc and it said to add 11lbs??? I can just dump it in front of the return. AG 13570 gal vynil.

Yes, I also calculate about 10 pounds which will not only bring your TA to 85 (assuming it truly is at 30 now), but will also raise your pH to about 7.1-7.2
BleachCalc is a great program and you can trust it for the calculations that it does.

However, play it safe and add about half or certainly no more than 3/4 of the amount, not all of it. Then retest your water and see where you are at. Yes, you can just dump it in front of the return. Baking soda is one of the most innocuous chemicals you will encounter. It has a slightly basic pH. If it's really powdery, it should dissolve fairly well. If it's clumpy, you might want to break it up a bit before putting it into the pool (though my experience is that it dissolves pretty well).

[EDIT]Realize that increasing pH with Borax will slightly increase your alkalinity as well (by about 5) so once you've dumped in half to 3/4 of the baking soda, start adding Borax to raise the pH to your desired level. When you're within 0.1 unit of where you want to be in pH, figure out how much more baking soda to add and you'll probably be right where you want to be.[END-EDIT]

Richard

[rnjng]

Richard,

Thanks for the help with the alk/ph leveling. Your were right, I baught 2-4lb boxes of baking soda and used a total of 7.5lbs. that raised my alk to 100, and my ph to 7.2. So I added about 1lb of borax and will see what we have later, but I should be right around the 7.4-7.8 range according the bleachcalc, if I understood it right. and that is were it should be, right.

[chem geek]

Richard,
So I added about 1lb of borax and will see what we have later, but I should be right around the 7.4-7.8 range according the bleachcalc, if I understood it right. and that is were it should be, right.

You shouldn't need to go as high as 7.8 so I would just shoot for the 7.4 and see how stable it is there. I'm off on vacation so was busy and couldn't get back to you right away. I'll be back after next week. Have fun!