I read some of the posts about using borate for raising pH rather than sodium carbonate and I was wondering how many people actually do this? My understanding is that the amounts of borate added when adjusting pH are much, much lower than adding borates for buffering, algae retardation, and water feel--so although not many people do the latter, there might be quite a few doing the former. If I understand correctly, borates also don't "go away" unless the pool is emptied. However, one of the posts mentions you have 50 ppm borates in the spring, it will decrease to 30 ppm come fall--is this due to splashing out, etc, or is there some other process I don't understand? I just want to make sure I'm not putting myself into a similar situation as our current situation with cyanuric acid from the previous owner (over 150 ppm, yikes).
Question about borates
- Thread starter presence52
- Start date
Welcome to TFP!
You are confusing borates with borax. Borax is used often to raise pH over sodium carbonate because it increases the pH while only giving a slight increase to the TA level. Sodium carbonate raises both pH and TA. Since most people using TFPC methods are not using acidic pucks they don't need to raise the pH too often and almost never need to raise TA, so borax is the easier choice in keeping things in check.
Borax does increase the borate level, however it would take 37 lbs to raise the borate level to 50 ppm in a 10k gallon pool. Unless you are constantly needing to raise your pH it is pretty unlikely you will add too much. Also excessive borate levels over 50 ppm are not an issue as far as pool chemistry is concerned, though it can cause the water to be a minor health concern for pets or other animals that might drink from it.
You are confusing borates with borax. Borax is used often to raise pH over sodium carbonate because it increases the pH while only giving a slight increase to the TA level. Sodium carbonate raises both pH and TA. Since most people using TFPC methods are not using acidic pucks they don't need to raise the pH too often and almost never need to raise TA, so borax is the easier choice in keeping things in check.
Borax does increase the borate level, however it would take 37 lbs to raise the borate level to 50 ppm in a 10k gallon pool. Unless you are constantly needing to raise your pH it is pretty unlikely you will add too much. Also excessive borate levels over 50 ppm are not an issue as far as pool chemistry is concerned, though it can cause the water to be a minor health concern for pets or other animals that might drink from it.
- May 23, 2015
- 25,786
- Pool Size
- 16000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Pentair Intellichlor IC-60
Being in Hawaii, rain and draining off excess water will be the largest source of boron decrease in a pool (or any chemical decrease for that matter). As Donldson has posted, most people experience pool water that has rising pH, especially folks that follow the TFPC Method of pool care (bleach is very slightly alkaline and SWG's tend to cause pH rise). So very few of us need to raise pH on any kind of regular basis. As also noted, while it takes 37lbs of borax per 10,000 gallons of water in total to raise the borate levels from 0 to 50ppm, it only takes takes about 20oz (1 lbs 4 oz) of borax to raise the pH from 7.2 to 7.4. So if one had to adjust pH weekly, it would take quite a while for the borates to build up assuming there is no fresh water exchange.
In a pool with falling pH and the need to add base, the better approach to supporting pH would be to increase the TA with baking soda to find a point at which the outgassing of CO2 from normal pool aeration balances the pH. It most cases, raising the TA to levels slightly higher than what TFP suggest (~100-120ppm), should be more than sufficient to support the pH fall.
In a pool with falling pH and the need to add base, the better approach to supporting pH would be to increase the TA with baking soda to find a point at which the outgassing of CO2 from normal pool aeration balances the pH. It most cases, raising the TA to levels slightly higher than what TFP suggest (~100-120ppm), should be more than sufficient to support the pH fall.
