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So here are my latest number:
FC: 1.5 (tested in the evening before I added more bleach)
CC: 0
Ph: 7.8
TA: 90
Hardness: 190 - 200
CYA: 40-50
Question:
I have some stain (yellow) in the bottom of the pool around the main drain. I think it is from last year when the pool was not opened (i bought the house last year).
Also some rust looking stains on the top tiles of the pool.
Any recommendation on how to approach these?
I'm not the expert here, but I can tell you that the first question that anyone will ask is "How are you testing your water? Pool store, guess strips, OTO - red phenol, DPD, or FAS-DPD? All here recommend that you do the basic tests yourself, partly because MANY pool stores do NOT give accurate results. The Taylor K2006 or the K2006-C are the test kits always recommended. They are the same except that the C kit reagents are 2 ounce rather than .75 ounce.
This link tells about the test kits (typically not available locally) and provides links to order from Amazon. http://pool9.net/testkits
I'll also tell you that with CYA at 40-50 ppm, you want to ALWAYS keep a minimum of 5 ppm free chlorine. This link explains why. http://pool9.net/cl-cya/
Do you know the make and rating of your pump?
Do you you fill from city water or a well?
Is the water clear, cloudy, greenish, blueish, swampy?
I bet someone who can answer your stain questions will respond soon, and they'll be better able to help you if you answer the above questions.
Good luck!
Pappy
Pappy's given you the basics.
Assuming your test #s are reasonably accurate...If you don't have the test kit Pappy mentioned, you should get it. Meantime, if your local WalMart has the HTH 6-way drop test kit, buy it and a gallon of steam-distilled water. Also get several jugs of plain 8.25% bleach...since we don't know the volume of your pool I cannot say how much to use. You can get the bleach anywhere. CostCo sells it too.
Again, assuming your test #s are accurate.....
For get TA and Hardness for now...they are fine--Hardness is a tad low, but right on the line of the 200-400 ppm level.
Your pH is at the high end, so I'd add a little Muriatic Acid or Dry Acid to get it down below 7.6, but always in the 7's. Chlorine is more effective at killing algae at lower pH levels and by 7.8 it has dropped off in its effectiveness.
Your FC is 'way low for your CYA level. At 40-50 your maintenance level of FC must be between 3 and 6, but when you have algae, you need to shock to an FC level of at least 15ppm. Since it's a tile pool, you can safely go well above 15, to even double that to have a better shot at killing the algae.
Each gallon of 8.25% adds 8.25ppm of FC to 10,000 gallons, but the 121 ounce jugs add less, about 7.8. Based on your pool size adjust accordingly.
A pound of Cal-Hypo (65%) will add about 7.7ppm of FC to 10,000 gallons and about 6ppm of calcium, so you may want to use that to shock your pool. WalMart does NOT sell anything stronger than 48% which is junk. You'll have to hunt for it.
Meanwhile, when your FC is up, brush your pool daily and carefully to knock the algae loose. Vacuum to waste once a day, too.