Borate level

[pakalrtb]

I do not have a test kit for borates. Can I assume that the borate level will remain unchanged over time ? Will I have the same final borate level if I dissolve 4 boxes of 20 mule team at the same time, as well as if I add 1 box a month ???
What I am trying to say/ask is if the borates are like the CYA, ie they can only go up , unless you chance some water.
P_

 

[zea3]

Here is your answer! From the thread So you want to add borates to your pool

If I want to raise that to the 50 ppm mentioned here and I add the 600 oz that doing so calls for, the pool calculator tells me that this would raise my pH by 6.12 and my TA by 109. So should I then add the acid to bring that back into range??

If you are adding borates using borax you need to add the correct amount of muriatic acid at the same time to keep the PH steady. Adding acid will not affect the borates in the water. It is very important that you rebalance the PH after adding borates. Even with borax and acid being added at the same time the balance may not come out exactly right and you need to check the PH and make any final adjustments as needed after everything has mixed for a few hours.

The borates level is like the CYA level, it will normally only go down because of water replacement (splash out, backwashing, rain overflow) so it only needs to be checked at the start of the season and any time you suspect significant water replacement has occurred.

Adding borax and acid will have a small effect on TA, but the borates PH buffer and the TA PH buffer are essentially independent of each other. It is still possible to change the TA after adding borates, it is just significantly more difficult.

 

[pakalrtb]

So can I increase the borate level over time or should I do it all at once. I think I read somewhere some saying that middle level of borates are actually bad.
P_

 

[chem geek]

If you are planning on using borates as a pH buffer or to inhibit algae, then add it all at once to get close to 50 ppm (somewhat less is OK -- anything in the 30-50 ppm range should be all right, but since it will only go down with dilution starting at 50 ppm is reasonable). Remember that if you add it using Boric Acid then this is slightly acidic (will lower the pH from around 7.5 to 7.2 if the TA is near 100 ppm), but if you are going to be using a Borax product (sodium tetraborate), then that is very basic/alkaline and will need Muriatic Acid (hydrochloric acid) to compensate for the pH. Read Adding Borates -- When and How for more info.

 

[pakalrtb]

Thanks kem, I have clear the concept of counterbalancing the acidity of the borax
But my question is: is there an advantage in adding it all in one time vs doing it overtime (months)?

 

[gordiec]

I think the point is that there are no benefits to adding borates to levels under 30 ppm -- other than the immediate cash outlay.

Borates do accumulate, so you will eventually get to the point where they do their thing. But they also get pumped out when back washing the filter and when you pump out rain water, so it might be hard to track your actual borate level over time.