How can I tell if I have algae?

[FormerBromineUser]

Been thinking.... Can you bite the bullet and get your FC up to 30? ChemGeek has recommended that your shock level be 40% of your CYA. That would put you at 48. Yikes. Lots of bleach. So I am thinking 30, rather than 25 would help a little. Also, rather than only adding once a day, do it twice a day.

[RaceAngel88]

Yes, I can definitely do that. I was tempted to put more bleach in this morning when I found it was only at 22. I'm willing to put bleach in 2 or even 3 times a day if necessary to get rid of any potential algae. Once I've got it at 30, and can maintain that level, how many days do I keep it there? I assume it's safe for me to get in the water to vacuum it, etc. at 30, correct? I think it just has the potential to make clothing fade at that level.

[FormerBromineUser]

Yes, it would safe to get in as you would still actually be below "shock level" for your CYA. Old swim suits are always advised when FC is above your "max" level on the best guess chart.

Testing and adding chlorine to maintain that 30 level 3 times a day would be great! You need to keep at it until the water is clear, there are no signs of algae, and you can pass the overnight test. Do you know how to do that?

[RaceAngel88]

Yes, I know how to do the overnight test, but with the CYA that high am I still looking to make sure there is not an FC loss of 1 ppm or greater?

[FormerBromineUser]

Maybe not, but let's see how it goes. I followed a thread where we stopped a high shock level slam at 2ppm loss, but that was after watching all other numbers very carefully. Again, let's see how it goes.

[chem geek]

Regarding chlorine oxidation of CYA, see Degradation of Cyanuric Acid. It take about 2.5 ppm FC to oxidize every 1 ppm of CYA. Lowering the CYA by 150 ppm would take 375 ppm FC so maintaining a high chlorine level over quite an extended period of time. It's not usually a very cost-effective way to lower it particularly if water replacement is not too expensive. In 12,000 gallons, 375 ppm FC is 35 gallons of 12.5% chlorinating liquid which at $4/gallon would be $140. 12,000 gallons is 16 ccf so water replacement would be comparable in price if it were $8.75 per ccf.

[FormerBromineUser]

I have horrible well-water too. I try to harvest rainwater as much as possible for my refills. But, I also purchased an expensive Hydropure MetalTrap which fits on the end of your hose. It does help. I then add the water into the skimmer so that the filter can trap a little of the metals too.

[RaceAngel88]

I'd never thought about trying to capture rain water to refill the pool--that's a great idea! I'm always thankful when rain water gets in there because that's less crappy well water I have to add. I've never heard of a metal trap but I googled it, and that looks like something that could really help me out. We had our water tested not long ago. I should look at that report and see exactly what's in the water that causes it to be so cloudy. Maybe the metal trap would help to alleviate that problem. Meanwhile, I still haven't gotten my PH down or my FC up high enough to be a shock level. I'm probably too conservative with the chemicals because I'm always afraid of adding too much. This morning the numbers were: PH=7.8, FC=26, CC=.5, CYA=120. I added more bleach and more muriatic acid. I'll test again this afternoon and just before dark.

[RaceAngel88]

I'm not sure what finally worked, but after about 12 days of working on this, I now have crystal clear water! I vacuumed and scrubbed the pool walls with a brush daily. I broke down and bought an Aquabot robot vacuum to help me out. I added a very small amount of DE through the skimmer, and started using skimmer "socks." I've had the chlorine above 30 ppm for 4 or 5 days now, and I've been testing and adding bleach as needed 3 times a day. CYA is still at 120. I don't think I'm getting an accurate reading on the chlorine level at night because I've been adding more bleach in the evening, and then re-testing the chlorine level at dark, and I feel like the bleach isn't evenly mixed up into the water enough by that point. The pump just isn't big enough to really get things stirred up good within a couple of hours. Therefore, my chlorine level probably isn't accurate at night. Sometimes it seems pretty high, and then it has dropped considerably by morning, even though I don't think algae is the cause. I'm going to go back to testing the water twice a day (morning and at dark) and only add bleach in the morning so it has time to mix up before it's tested again that night. Then I'll see if the chlorine level holds for the overnight test. I'd like to let the chlorine level drop down to normal range by this weekend.

[swimdaddy]

Glad to hear you pool is looking better. Keep it up! Your pump is probably fine, its the filter that is too small, but anything is manageable.