So long story we have a little 3000 gal pool that my wife and I enjoy sitting in and relaxing. We "upgraded" this year from the easy fill pool to the metal frame liner pool and all was well until we started to see some algae on the bottom. We have been fighting it for a couple weeks now. Well after a couple inches of rain from the hurricane that just went through we woke up and the pool was covered in algae and turning green. We always kept the chlorine a bit on the high side because it is always hot and humid here in south Alabama but from what I read the big mistake was deciding to use the floater with hockey pucks maybe. We had a cheap test kit and knew the chlorine was high and didn't understand why the algae appeared. So in a small town we only have a Walmart for pool supplies so off we go to get some shock. They had a 1lb bag HTH I think was the brand and it said 1lb was enough for 13,000 gal so we divided in thirds so should have been enough for 4000 gal. We put it in the pool ran the filter over night and the next day it was still pretty green and algae on the bottom. So we decided to put the rest of it in there enough for 13k gallon total in 24 hours. It has helped but still have some algae on the bottom of pool every evening. The pump has been running nonstop for 7 days and I clean or put new cartridge in it daily. I vacuum and brush the bottom twice a day. It seemed to be clearing up and yesterday noticed some greenish foam on the surface around the vacuum hose re-appearing so my patience were lost and I added a BUNCH of powdered chlorine I had left over before we switched to the pucks. Okay now we got the good test kit recommended on here TF-100 so we tested just now and....Chlorine was off the chart which is expected because I basically tried to shock the pool with the powdered chlorine yesterday. The other numbers are FC-18 CC-.5 so TC=18.5 i think? TA-90 CYA-80 PH-7.8. Any help would be appreciated.
After algae bought a real test kit now need help
- Thread starter widfarm
- Start date
- May 3, 2014
- 58,656
- Pool Size
- 6000
- Surface
- Fiberglass
- Chlorine
- Salt Water Generator
- SWG Type
- Pentair Intellichlor IC-40
Welcome to the forum! :handshake:
You need to SLAM Process. Your pH is not an accurate test with your FC above 10 ppm. So if you test your FC later today see if it has fallen to 10 ppm If so, test your pH and then lower it to 7.2 with muriatic acid.
Then use the [FC/CYA][/FC/CYA] for your shock level FC based on your CYA of 80. Or, drain off half your water and replace with fresh to lower your CYA to 40 ppm and then your shock level FC will be lower.
I suggest you read Pool School - ABCs of Pool Water Chemistry and consider reviewing the entire Trouble Free Pool School book.
You need to SLAM Process. Your pH is not an accurate test with your FC above 10 ppm. So if you test your FC later today see if it has fallen to 10 ppm If so, test your pH and then lower it to 7.2 with muriatic acid.
Then use the [FC/CYA][/FC/CYA] for your shock level FC based on your CYA of 80. Or, drain off half your water and replace with fresh to lower your CYA to 40 ppm and then your shock level FC will be lower.
I suggest you read Pool School - ABCs of Pool Water Chemistry and consider reviewing the entire Trouble Free Pool School book.
Thanks for the advice. I will wait for the FC to drop and retest the PH. I have had a problem keeping it down so I have some muriatic acid here. So is your opinion to discontinue using the hockey puck chlorine? Maybe liquid bleach instead?
I assume the high CYA is what caused the problem? Will the CYA go down over time if I change to liquid chlorine?
- May 3, 2014
- 58,656
- Pool Size
- 6000
- Surface
- Fiberglass
- Chlorine
- Salt Water Generator
- SWG Type
- Pentair Intellichlor IC-40
CYA is in the pool water unless you remove the pool water with it in it. That is why I suggest draining half the pool volume and replacing with fresh water.
Solid chlorine (pucks, granules) are not sustainable in daily use. They are OK for use while away for a few days, etc. For daily use liquid chlorine is suggested.
Solid chlorine (pucks, granules) are not sustainable in daily use. They are OK for use while away for a few days, etc. For daily use liquid chlorine is suggested.
Okay I drained almost half of the water and I would say my CYA is 45-50 now. I tested the PH and it was 8.2 so I used the pool calc and put muriatic acid in and it came down to 7.2 perfect! i then used the CYA/FC chart to determine shock level. I went to the calc and got the right amount of liquid bleach to use. My goal was 20ppm and later that evening after dark I did the over night test. It was 15.5 in the evening and in the morning it was 15 with no CC and water looked clear but had some greenish on the bottom that I vacuumed up. Just in case I added more bleach to shock level yesterday morning. I was not home last night to test but this morning it is at 13ppm. Now it was sunny yesterday and it has been about 26 hours since I added enough bleach to take it back to 20ppm. Does the 7ppm drop seam appropriate for the time frame? I will test it over night tonight but I guess I will leave it at 13 for now as according to the chart my goal with cya 45-50 is 6-7ppm. My other question is is that a safe level to swim in? Also now 2 days later my PH went back from the 7.2 to 7.8?? I added more acid according to the chart hopefully I was suppose to do that.
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