Quote Originally Posted by waterbear View Post
A few thoughts:
50 ppm borate is fine in my opinion.
Thanks.

A cheaper source of borax is 20 mule team borax from the grocery. It's the same stuff except that it is the decahydraate form (it has 10 water molecules attached instead of 5) so you need a bit more by weight for the same borate level (60 oz by weight will raise 1000 gallons 50 ppm and needs abut 30 fluid oz of muriatic acid to keep the pH in line. The pentahydrate form requires about 45 oz by weight and the amount of acid to achieve 50 ppm rise in borate in 1000 gallons while using boric acid requres about 38 oz by wieght and will very slightly lower the pH but this is not a concern since it will rise on it's own as CO2 outgasses.)

If you want a pH neutral borate souce that is available commercially then Proteam Supreme Plus is the product you want. Proteam Supreme is exactly the same at Bioguard Optimzer (sodium tetraborate pentahydrate). The Supreme Plus is a mix of boric and and the pentahydrate form of borax to make it pH neutral. However, all the commercial forms of borax are MUCH more expensive than 20 mule team borax from the grocery store.
Great information. Regarding cost, the last time I bought BioGuard Optimizer, spring 2011, I paid about $40 for a 20# bucket, so about $2/lb. A quick check online showed 20 Mule Team Borax close to that, about $1.70/lb. So I really didn't pay much more, perhaps about even or less when you consider you don't need as much to achieve the same borate level. That said, I just did a quick online check for Optimizer and found a 20# bucket running about $60. Not sure why I got it so much cheaper at a local pool store last year. Out of curiosity I'll call them tomorrow and see what they currently charge. If it has gone up alot, then I'll switch to borax. I also did an online check for boric acid and it was very expensive, so that option is out (it would be nice not to have to add so much acid). Proteam Supreme Plus also looks to be very expensive.

The main reason to use sodium hypochlorite (particularly since you have a vinyl liner) is that calcium hypochlorite is slow dissolving and can bleach the liner if it falls on it undissolved. Also, Sodium hypochlorite is what the salt cell is is actually making. As far as worrying about the 'freshness of the bleach" it's really a moot point. Unless you are buying it at a discount store or dollar store it's probably fresh. Walmart has a big turnover so it's a good place to buy it. If they sell pool chlorine in refillable carboys in your area that is often the best deal. Just buy enough for shocking and don't stockpile it so it does not stick around for more than a month or two before getting refilled. One gallon of 12.5% pool chlorine will raise you pool about 6 ppm, btw, so a 2 1/2 gallon carboy should be just about right for shocking your 22000 gal pool (or 5 gallons of 6% laundry bleach). If you use cal hypo predissolve it first. You do not want undissolved cal hypo going through the salt cell or falling on your liner.
Understood. I don't put dry cal hypo directly in the pool; I've always pre-dissolved it in a bucket then put it in the pool. Using this method I've not had any issues with the liner. I'll have to check local prices for bleach. Locally I pay $2/lb for 68% cal hypo. I buy it by the bucket, 40-50lbs, instead of by the 1lb bag which is much more expensive.

As far as your metal problem, Were the stains brown (iron)? Do you fill with well water? What kind of salt do you use? I have seen some fine crystal "pool salts" that have caused iron staining which is why I recommend using solar water softener salt (The larger crystals do not need anti caking agents). I suspect that anti caking agents are sometimes added to the fine crystal pool salt or they are using food salt (which also contains anti caking agents) and repackaging it. Yellow prussiate of soda (sodium ferrocynaide, an iron salt) is used as an anti caking agent in food salt.
Yes, the stains were brown and disappeared almost instantly when ascorbic acid was applied. We are on city water which comes from a reservoir, not wells. I use "pool salt" from the pool store. I was told it has no anti caking agents. There was nothing on the label to indicate either way, so perhaps it did have some kind of additive? During my first season with the pool, I tried using solar water softener salt (how pure is it?) but the large crystals took so long to dissolve it was very time consuming and a pain to add salt. I did notice that this year my pool store is selling a different brand of pool salt. The brand is Aqua Salt ( http://www.aquasalt.com/aquasalt/web...t_overview.htm ). I just took a look at the bag and just noticed it says "Enhanced with a natural stain fighter". Is this a bad thing? Or would using this salt eliminate the need for the Purple Stuff?

That brings up a question. Let's assume that the salt I've been using does have an additive that's introducing iron to the water and in turn is the cause of the stains. As I understand it, Jack's Magic Purple Stuff is a sequestering agent that keeps the metals in suspension. The manufacturer says it allows the filter to remove the metal, but I read that it merely keeps the metal from coming out of suspension and attaching to surfaces such as the steps and liner. Please correct me if I have this wrong. So if the metal is staying in the pool, is the only way I could get away from using the Purple Stuff is to do a complete water change and start over using solar salt, assuming it has no metals in it (do we know this?)?

If I could get to the point where I didn't need the polyquat and the Purple Stuff, that would save me about $400 a season (it cost about $200 for each per season). Up until now I've just accepted the extra expense because since adding them to my routine I've not had any algae problems or staining problems (note that I started using polyquat and borates about the same time, so I really can't say if the polyquat is making a significant difference).

Thanks again for the great feedback. This is very educational and helpful.