algae when running pump

I only see the algae after running the pump. PH is 7.5 chlorine is 5-6 with dpd test kit. Chlorine has been high for long time. what about leslie's pool first aid. will it help?

Running the pump might stir up algae, but it doesn't cause it.

Read the Best Guess page linked in my signature -- odds are, your CYA level is so high, that an FC level of 5 - 6 is LOW, not high. If you've been using trichlor or dichlor to chlorinate for an extended period of time, this is almost certainly your problem.

You'll need a Taylor K2006 kit from Amazon to test, and then manage your pool. Strips are inaccurate, and are HORRENDOUSLY inaccurate at testing CYA (stabilizer).

Links for test kit info, and my Best Guess chart, are in my blue signature block.

hi, thanks for the reply. how can I lower the CYA levels? aqua chek strips say around 100.

my FC is high at 10 now after taking your advice from here:
http://www.poolforum.com/pf2/showthread.php?21881

I raised the ph to 8 with soda ash. alkalinity stayed the same. i will try the borax now because algae isn't gone.

i use a dpd test kit with taylor chemicals to test for cl and ph.

To reiterate some of what Ben told you above:

You cannot trust the CYA results measured with test strips. You need to do a "disappearing black dot" test. If your CYA s high, you have two choices.
1. You can do a partial drain and refill.
2. You can compensate for the high CYA by running higher than normal chlorine levels. (Please read the Best Guess Chlorine Chart in my signature below.)

Although we recommend the Taylor K2006 kit to everyone, if you run a high chlorine high CYA pool, it is an absolute must.

If your pH is 8 (and you cannot trust that reading if it was taken while your chlorine was high) , you do not want to add Borax right now.

If you have algae, you have to get your chlorine up high enough to kill it and it is based on your CYA level. (Again, info in the best guess chart.)