We are also new pool owners and are fighting mustard algae. We have a 27,600 gallon IG with a Hayward S240 Sand filter, vinyl liner, pump size is AO Smith 1 HP 3450 gallons per minute with a flow rate of 63 gpm. After vacuuming for the 4th time in 7 days, our chlorine level is 1.2 Ph 7.5 Alk 90 Ch 180. Please help!!!!
New Pool Owner Needs Help Fighting Mustard Algae
- Thread starter biggun
- Start date
Hi, thanks for posting your test results. Do you have a result for CYA? We need to know your CYA level to calculate what your shock level should be. Do you have a test kit or do you take your water to be tested at the pool store?
Just got the TL-100 Test kit today with XL option. Today the chlorine is 5.5, Ph 7.4 Alkalinity is 70 and CYA is 72. any help will be appreciated.
where do i get calcium chloride, this oil field country is it possibly available from a mud engineer
You are going to have to shock your pool at mustard algae levels to get rid of your MA problems. Read up on this in Pool School at the top right corner.
Your calcium is fine for your vinyl liner pool.
Your calcium is fine for your vinyl liner pool.
We went through this about the first week of August (we were all gone with no pool sitter). We researched TFP and found that Super shocking the water will kill the mustard algae, so that's exactly what we did. We brought the FC up to about 20ppm to kill it off. For our 23k gallon pool it took 10 bags of shock. The day following the shock, we brushed and vacuumed all the algae that had settled and then immediately cleaned the filter. We repeated the brush/vacum/filter cleaning process again for 2 more days and the water has been crystal clear ever since. The FC came back down to normal after about 4-5 days. We didn't swim on shock day and day 2. After that it was game on. May be a bit amateur, but we're new at this as well and it worked for us. BTW, we also use the TF-100 super size kit to test.
Your CYA is high, unless you have a saltwater chlorine generator. Let's confirm that you have mustard algae. Is it growing on the sides of the pool in shady areas, or do you only see accumulations settled into the dips and wrinkles in the bottom of the pool? Is it slimy to the touch or does it seem to "disolve" in a powdery cloud? Any pictures you could post would help as well.
If it is mustard algae, then with a CYA of 70 (rounded off for simplicity) your shock level would be 39 ppm of chlorine (15 gallons of plain, unscented 6% bleach). Since your CYA is so high you will want to use liquid chlorine (bleach), which will not add more CYA to the pool. Not only would you need to raise the pool to shock level you would need to keep it at shock level until you passed the overnight test. If you truly have mustard algae I would recommend a partial drain and refill to lower the CYA level, which in turn would lower your shock level.
If it is mustard algae, then with a CYA of 70 (rounded off for simplicity) your shock level would be 39 ppm of chlorine (15 gallons of plain, unscented 6% bleach). Since your CYA is so high you will want to use liquid chlorine (bleach), which will not add more CYA to the pool. Not only would you need to raise the pool to shock level you would need to keep it at shock level until you passed the overnight test. If you truly have mustard algae I would recommend a partial drain and refill to lower the CYA level, which in turn would lower your shock level.