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fresno49
08-15-2013, 03:17 AM
hello from very hot and sunny central ca. I'm having a algae problem and hope u all can help I can't seem to get rid of what I believe to be dead algae on the bottom of the pool I have new d.e. grids in filter ,pressures good, backwash regulary, sweep every nite but the next evening its the same way it was the day before. I don't think its a its a filter problem, maybe circulation there doesn't seem to be suction at bottom of pool, also p.h. is fine but can't get chlorine level up Please Help thanx in advance
Kev

PoolDoc
08-15-2013, 12:23 PM
I have new d.e. grids in filter

+ If it's in piles, and is grayish in color, it's probably DE powder that leaking from your filter, possibly due to a cracked DE grid or a misplaced air relief line.

If so, you'll have to repair the filter.


+ If it's brown-ish / yellow-ish / green-ish, with no depth, and will brush away in a greenish cloud, it's mustard algae.

If so, you need to

+ read the Best Guess page (linked in my blue signature block)

+ find out what your CYA level is -- by testing with a LIQUID test. (Strip test for CYA are *horrendously* inaccurate.)

+ get your chlorine level up. On Google Maps, your pool looks like it's in the 30K gallon range. (I'm the ONLY one who can see you address info -- it's not available to the mods.) That gives you a PF of ~4, so 1 gallon of 8.25% PLAIN household bleach will add about 3 ppm of chlorine.

Add *FOUR* gallons of bleach this evening (not afternoon; not morning).

+ get a cheap OTO / phenol red kit (yellow / red drops). Test your pool the following morning. If you do NOT have a DARK yellow result, you probably do have mustard algae.

+ Continue dosing with 4 gallons of bleach nightly, till you have a DARK yellow to orange reading in the AM. Brush all the spots after the 2nd bleach dose.

+ Order a Taylor K2006 kit from Amazon (link in my sig) so we can find out what's really going on with your pool. Do NOT get a K2005, which may be locally available; get a K2006 which is not.