In spite of these facts which I have relayed in turn to the HOA board members they are insisting that we NOT reduce the water level citing water costs. They do not seem to comprehend that the CYA will not go away like chlorine does.chem geek wrote:The following are chemical facts that are independent of concentration of product or of pool size:
For every 10 ppm Free Chlorine (FC) added by Trichlor, it also increases Cyanuric Acid (CYA) by 6 ppm.
For every 10 ppm FC added by Dichlor, it also increases CYA by 9 ppm.
For every 10 ppm FC added by Cal-Hypo, it also increases Calcium Hardness (CH) by at least 7 ppm.
You are right that with your high CYA especially, and to a lesser extent with your somewhat high (though still manageable) CH, you need to dilute your water to lower these levels. As you can see from the above, even at a daily 1.5 ppm FC per day loss which is what you are seeing, that's an increase in CYA of over 25 ppm PER MONTH from Trichlor.
You need to check your county/state regulations since your HOA may fall under commercial/public pools and have very specific requirements for various chemical levels. If there is a maximum FC limit that is lower than I suggest, then you'll have to follow that limit and use alternative means to prevent algae growth, such as using Polyquat 60 weekly (at extra cost).
With your 100+ ppm CYA, if you maintain the FC level at around 10 ppm using chlorinating liquid or bleach so as not to raise the CYA nor CH levels, then you will prevent algae growth unless the CYA level is more like 200 ppm. With your high CYA level, a high FC level will not be harsh on swimsuits, skin or hair. 10 ppm FC with 100 ppm CYA is roughly equivalent in active chlorine level to a pool with only 0.1 ppm FC and no CYA. The only issue with the higher FC level is if people were to drink very large quantities of pool water on a regular basis (which obviously they shouldn't be doing anyway).
You should get your CYA level closer to 50 ppm. You should also consider using chlorinating liquid and getting an automatic dosing system such as a peristaltic pump or The Liquidator . If you want to continue to use Trichlor tabs, then you'll need to use a supplemental algaecide such as Polyquat 60 weekly or a phosphate remover or use 50 ppm Borates. Even so, the regs will probably require you to dilute the water to keep the CYA under 100 ppm.
They won't even pay for the TF100 kit which I feel will allow me to be more effective in keeping things under control. I put 2lbs and about 8oz of cal-hypo in yesterday (Sunday) morning based on the most recent chlorine levels and brushed the sides beforehand. I also put in some clarifier since there are visible particles in the water when I look at night that are just not being filtered out. By 3:30pm the water had really cleared up. But I cannot even measure the chlorine now to know whether it's correct or not. If I put enough in there it should be around 10ppm or so FC which is high-middle of the 8-13 FC range based on CYA=100.
For now the feeder is off. Unless it's valve leaks it should not be providing any chlorine. So the only chlorine added in the last week was last Sunday and yesterday. Both times I added around 2 lbs. If I could do that weekly for the rest of the summer it'd be fine actually. I still need the test kit so we don't have to rely on pool store people for the tests.
As for regulatory stuff. We are complying with local city of Houston codes that indicate we are a private pool, not either commercial nor public or semi-public. This has to do with the size of our community being 30 condos or less. They city doesn't even issue a permit for us and when requested to issue one we were told "no". So, unless we have a green pool which would be a violation of code, we're square.
State law seems to govern (semi)public pools and has little to say about private pools. And there is no CYA minimum or maximum as far as I can find in the commercial codes so that's OK too. FC is supposed to be 2ppm or more for state and local codes which is ok for us.
Our homeowners' cats sometimes drink the pool water for some reason. Otherwise I don't think we have too many people drinking it.
Thing is I've been told to keep out and we still don't have a pool service. Two relative novices who are my neighbors one being a board member (there are only three) have decided they know more about pools and to believe only those at Leslie's pools. I've tried to explain the chemistry stuff of CYA needing to be diluted by partial drain/refill and sent them both links to the pool school and such, but they both refuse to educate themselves about this. One of them was told the CYA would evaporate over time. ARG! And she believed it. There is no way I'm going to convince these two people to change to liquid chlorine if they won't even buy a test kit, but continue to rely on Leslie's for tests. I'm so frustrated with these idiots I can't think straight.
Sorry, I feel I'm ranting a little here...
I wish they would just hire someone, but even that seems to be failing because they don't want to spend the money. Does $350 a month including chemicals seem too high? I know this varies by market but is that outlandish or about average?