pH help!

Equipment:
Water pump
Air stones with air pump
Hanna pH and EC meter
~3 gallon tub
200 watt CFL

I'm on a seedling stage, so it's just the water, but I've been trying to keep the pH at 5.8-6.1 and on a day-to-day basis the pH is increasing quite a bit. I keep adding pH down to it to get it back into range, and then by the end of the day (or the next day) it is increasing! The plant can't possibly be doing this as it did it before I even put in the seedling. The temperature of the water is ~79-81 degrees with air temp being 75. The light is on 24/7, is there maybe some stuff growing in the water that is increasing the pH? Can I fix that? I've put aluminum foil over the container with the exception of around the seedling... no idea what to do. Help!

Are you using any nutrients yet or is it just water and the pH down? What is the EC in the reservoir?

Small amount of nutes, I adjusted pH before, after, and 24 hours after adding nutes. There is a low level of technaflora's sugar daddy and some vitamin B. I'm away from it, but iirc the ppm is around 130.

No answers? Cmon guys

diradiumoxide said:

Small amount of nutes, I adjusted pH before, after, and 24 hours after adding nutes. There is a low level of technaflora's sugar daddy and some vitamin B. I'm away from it, but iirc the ppm is around 130.

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I never adjust until after adding nutes. If you're using airstones that can bring up the ph. I use a little pump to recirculate my water and doesn't seem to effect it any. Algae can eat up your nutes, which i believe can also mess with ph a little.

your res temp is way to high for starters,and if you have stuff growing in your res thats your problem dump the res and start over and keep the res cooler 65 to 70

Couple of things;

Cool you res back to 75 (at MOST)
Be careful of you pH adjusting you have probably skyrocketed your PPM, and not added anything useful
Your problem is likely algae. Algae consumes the CO2 in the res and drives the pH up usually between 1 and 2 full points a day.
Start adding 10 mL 29% Oxidizer H2O2 to your res every week until the pH stabelizes. Keep in mind though a slight rise in pH is entirely natural. After the pH stabelizes decrease frequency to once every other week and make this part of your routine.

Are you trying to lower it to 5.8? If so, that's a bit harder. You need to overcome the calcium carbonate buffers in the water. No matter how many times you pH down, it will rebound back to the original value due to the action of the buffers in the water. Raising pH is not all that hard, but if you have alkaline water from the tap, you are in for a struggle. Read these links, what ever is good for an aquarium is also good for your plants.

http://freshaquarium.about.com/cs/waterchemsitry/a/mathcph.htm
http://www.algone.com/aquarium-articles/technical-aquarium-information/aquarium-water-parameters
http://extension.usu.edu/files/publications/publication/NR_WQ_2005-19.pdf

i had this probem in flowering with the ph rising all the time! i started using h202 and it cleared things right up. it kills and disinfects ur buckets and resovour. i think pathageons start up when the water temps rise and this will help,