dead algae?

[fresno49]

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]

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.