PH REFUSES to stay up

jag1979 · #1 11/10/2006, 11:14 AM

I thought I would start a new thready because my last one turned into something else.

I cannot get my PH to stay above 8. I began using buffer, but per Randy's afdvise stopped because my alk was getting to high. Then for a while my ph stayed in the 7.92-8.10 range. Two days ago it dropped to 7.55 in the morning. I re-calibrated my probe and got a reading of 7.98 last night, I added some kalk and it raised to 8.24...Great! This morning it was 7.74 so I added some more kalk to raise it to 7.91.

WHAT IS GOING ON W/ MY PH???

zily · #2 11/10/2006, 11:26 AM

get some more plants. If its low in the morning (when the lights just turned on) and high at night, it's probably the photosynthesis from the algae in your tank that raises pH (plants use CO2, which will lower the carbonate (acid) concentration).

Do you have a sump tank? If you don't, you might want to think about getting a sump with a light for the night and algae growing in there. Good nutrient export also. And if you could keep it stable at 7.9, that's probably better for your tank than having it flucuate from 7.9-8.3 with kalk.

jag1979 · #3 11/10/2006, 11:30 AM

can i put some macroalgea in the overflows to act as a refugium?

jag1979 · #4 11/10/2006, 11:31 AM

I do have a sump, but not sure if I want to put a light on it

zily · #5 11/10/2006, 11:31 AM

yeah, it will raise the pH during the day, but unless you have a light over it at night, the pH will go down by the morning.

How big is your tank btw?

jag1979 · #6 11/10/2006, 11:34 AM

I have a 180 w/ two overflows and a 60 gallon sump. I really have too many things in the sump to turn part into a fuge: 6" fan blowing directly into the water, return from UV, two heaters, skimmer, pump, tubing running across...

zily · #7 11/10/2006, 12:15 PM

well add a light to the list

Also, if you want to try some other methods, you could run the bubbler in your skimmer from a window to get some fresh air from outside. But the most noticeable difference is going to be some more macro algae photosynthesizing at night.

Maybe someone else has another idea. Good luck!

jag1979 · #8 11/10/2006, 12:19 PM

thanks, I'll try to figure out a way if I need to

about macroalgae, Do you just throw it in? you don't have to attach it to anything?

zily · #9 11/10/2006, 12:40 PM

yeah some stuff just kinda floats on the top of the water-- maybe put a plastic container colander or something around it to keep it from floating away or getting in the powerheads.

Some algea also attached nicely to rocks, including a nice infestation I had at one point.

Randy Holmes-Farley · #10 11/10/2006, 05:05 PM

If you are confident the pH calibration fluid was good, then I'd do the aeration test on your inside and outside air:

Low pH: Causes and Cures
http://reefkeeping.com/issues/2004-09/rhf/index.htm

apache73 · #11 11/10/2006, 11:46 PM

Quote:

Originally posted by zily
get some more plants. If its low in the morning (when the lights just turned on) and high at night, it's probably the photosynthesis from the algae in your tank that raises pH (plants use CO2, which will lower the carbonate (acid) concentration).

Do you have a sump tank? If you don't, you might want to think about getting a sump with a light for the night and algae growing in there. Good nutrient export also. And if you could keep it stable at 7.9, that's probably better for your tank than having it flucuate from 7.9-8.3 with kalk.

Are these macro-marine algae like FW plants? That is, actually consume O2 (at night-or no light period) thereby causing the PH to decrease at night?

G

zily · #12 11/11/2006, 01:11 AM

Yeah I suppose--keep in mind that plants use a part of photosynthesis (the calvin cycle) for a while at night using the reserves they've built up during the day. But eventually they run out and the plant will burn sugar for energy, and lower the pH.

And I say macroalgae soemtimes insteaqd of plants because algae is technically in the kingdom protista instead of the plant kingdom... which is kind of werid and annoying. But as far as I'm concerned, algae =plant.

Randy Holmes-Farley · #13 11/11/2006, 08:09 AM

All organisms in a marine aquarium will release CO2 at night and contribute to pH dropping, but macroalgae do have a net boost to pH, and if you light them 24/7 or on a reverse light cycle, they can boost pH a bit just when you need it.

BUT, macroalgae are rarely a solution to severe low pH by themselves. Limewater and more fresh air are by far the best solutions.