A few folks asked for a sticky on this so here it is. If you just want to jump to how without the why look for the blue part of this post below!
Several companies are selling sodium tetraborate pentahydrate as a pool additive under such names as Proteam's Supreme, Bioguard's Optimizer Plus, Poollife Endure, Guardex Maximizer, and others. Several claims have been made for these products when used in a 30-50 ppm concentration such as:
1) more stable pH
2) Algaestatic properties
3) reduced chlorine usage
4) silkier feeling water--less skin and eye irritation
5) clearer, 'sparkling' water
Do these products live up to the claims made for them?
A definite YES!
Remember that all pools are different so you might see dramatic results or just a slight improvement. There are a lot of other factors that come into play. Do borates help simplify pool maintenace? Another definite YES!
Are there any downsides to adding borates?
I can only think of two.
1) They are an additional expense
2) There has been some concern of toxicity if dogs drink large quantities of water from the pool.
I do have to say that most people find that their pools become much easier to maintain once the borates are in and several people on the PoolForum board have reported that since adding borates they have not had any mustard algae outbreaks.
As far as dogs (or people) ingesting small amounts of pool water, that's not going to hurt then BUT if you dog things the pool is their own private giant water dish that is NOT a good thing, borates or not! There are may chemicals in our pools that are not really good for our pets to consume in large quantities! Provide fresh drinking water outside and change it regularly and it's pretty easy to teach your pets not to drink from the pool! (I know a bit about this, I have three dogs and a cat!)
Do I feel the benefits of borates outweigh the downsides?
A RESOUNDING yes!
Just remember that adding borates are not going to magically cure your pH problems or algae problems and they are NOT going to relieve you of having to test and balance your water!
They will just help make these jobs easier!
You can also use sodium tetraborate decahydrate (20 Mule Team Borax) to achieve the same results for a much lower price.
Here is how to do it:
You will need a bunch of 20 Mule Team Borax and 31.45% Muriatic Acid. Don't forget some borate test strips! The LaMotte Borate test strips are the best ones I have come across.
1. First, adjust your TA to your target value. (This is actually the hardest part of this whole procedure.) This should be around 70-80 ppm for SWGs and liquid chlorine (or bleach), around 100 ppm if you are using trichlor. The borates will cause a very slight increase in the TA when you are done.
2. After TA is at target value adjust pH to between 7.4-7.6 (This is the second hardest part!)
3. Figure out how much borax and acid you need. An easy way to do this is to remember that 12 oz. BY WEIGHT of borax raises 1000 gallons 10 ppm and requires 6 FLUID oz. of acid to neutralize the pH rise. This is not exact but it's close enough. Remember, we are talking about a pool, we're not making rocket fuel here!
So, if 12 oz. of borax raises 1000 gallons 10 ppm and we want 50 ppm we need 60 oz. of borax for every 1000 gallons in our pool. Likewise, we would need to add 30 oz. of acid for every 60 oz. of borax! Here is an example:
Let's say we have a 15000 gal. pool, then we would need 15 X the borax needed for 1000 gallons which is 15 X 60 = 900 oz. by weight. Let's convert that into pounds by dividing by 16 (16 oz. per lb. or we could write that 16 oz./lb.) That would be 56.25 lbs.
Each box of borax weights 4.75 lbs. or 76 oz. so here is a faster way to figure out how many boxes you need:
number of oz. needed / 76 oz. in a box = number of boxes needed so in our example we would have:
900 oz. borax / 76 oz. per box = 11.8 boxes. Remember it's not rocket science so use about 11 and 3/4 boxes or just use 11 or use 12. You will end up close enough to 50 ppm!
Now for the acid. we need 30 oz. per 1000 gallons to neutralize the pH rise of 50 ppm borates and we need to multiply that amount of acid by 15 since we have a 15000 gallon pool. That comes to 15 X 30 = 450 fluid (liquid measure) oz. of muriatic acid. There are 128 oz. in a gallon so we divide our amount needed in oz. by 128 to find out how many gallons of muriatic acid we will need.
For our example this is 450 oz. / 128 oz. per gallon = 3.5 gallons of muriatic acid. If you follow along on a calculator you can see how I am rounding off to the nearest EASY measurement. Once again, REMEMBER, it's a pool, you're not working in a chemistry lab!!!!!!!! We will balance out any slight inaccuracies a bit later so don't worry. It's all good!
Now take a deep breath, the worst is over!
4. WITH YOUR PUMP RUNNING add 1/2 the required acid to your pool. You can pour it SLOWLY into the stream of one of your returns or dilute about 1/2 gal at a time in a 5 gal bucket of pool water and broadcast it around the pool. As soon as the acid is in put in 1/2 the borax. Just dump it in the water or pour it in your skimmer.
5. Brush down the sides of your pool all the way around. This will create currents that mix everything. You are 'stirring' your pool water by doing this. This is a good procedure to follow when you add any chemicals to your water and want to mix them. Anyway, none of us really brush our pools enough, do we?
6. Add the rest of the acid and the rest of the borax and brush just like you did for the first batch. You don't have to wait, just put it in when you finish brushing.
7. Brush again!
8. Let the pump run continuously for 24-48 hours.
9. After 48 hours (not sooner please!) test your borates. You should be right around 50 ppm. Now test your pH, if it is above 7.6 add a bit more acid to bring it down to about 7.6. If you pH is below 7.4 you can start aerating to bring it up unless it's below 7.0, then you need to add more borax.
10. Test your borate levels monthly. If you backwash a lot you might need to test a bit more often. When your borates drop to about 30 ppm increase them another 20 ppm to bring them back up to 50 ppm by adding the acid and borax. This time you don't have to divide it into two batches. Just make sure your TA and pH are in range then add the needed acid and borax and brush. Check your levels in 48 hours and make any minor adjustments that might be needed. If you have a cartridge filter you will find that you borate levels stay pretty stable (unless you have a leak somewhere! )
11. Enjoy the sparkling water, the reduced chlorine demand, the pH stability, and the algaestatic properties that the borates have added to your water. The 'sparkle' has been commented on by just about everyone who has done this. The water looks almost jewel like!
If that is too much work and you don't mind spending the money then Proteam has Supreme Plus and Haviland has Salt Support. These are both pH neutral products that do not require the addition of acid along with them. They are the only two pH neutral borate products I know of. The Salt Support also contains some CYA I believe but I have not been able to confirm this. They are more expensive than the regular borate products and MUCH more expensive than 20 Mule Team Borax but only you can decide if the convenience is worth the extra expense to you.