Whats the longest lasting ph down???

been using AN ph down and it works amazing. but i just moved and have a different setup and different chemicals and the ph is needed to be changed every 12 hours.... i have a 55 gallon tote and i have to scoop like 2 big scoop of GH ph down powder to drop the ph every day. AND every scoop is like 150 ppm/e.c added!!!!!!!!! so its ridiculous product that dont do its job and burns my plants in 4 days of a new res change. d
does this sound like ph down powder to yop or is mine old or something? either case prob should start buying phosphoric acid just wanted to rant about how gh is the shitty est nutes ive ever used.

sounds like you should go back to AN.

fellow growers round here often use this and have good results..
http://www.hydro-organics.com/home/index.php?categoryID=568

I've never had a problem using gh up or down. Your ph should be much more stable then that. What are the temps? Sounds like something else is going on.

^^^ I agree with Squidbilly, I have used gh for several grows and ph swings never happened.
I add my base nutes, add my few if any additives and ph down to 5.8. Stable for 7 days in a 35 gallon res.

I never noticed an increase in ppm from ph down, I check my ppm level before and after. I would have a good look at the rest of the picture.
Temp and res. circulation would be a good place to start. A stagnant res can do very odd things over time.

Peace and Great Grows

Asmallvoice

clean it out every time you change the water.
once a year with a 5% bleach solution.
lines and pumps and everything.

do you measure a different ph after each feeding?

Yup me thinks you have an issue that does not relate to the actual up. Try using the AN product again to see but pretty sure it'll be the same until you fix the other issue. I add down when refilling to bring it down to 6 ish and then watch it, it never goes up and after 3-4 days it will slowly drop. At 5.8 i change res again. This typically happens every 7 days early flower and every 5-7 days near end. I have found with my setup that adding up at the end is a waste of time and only refilling will bring it up and stabilize there.