High Alkalinity / Low pH questions

yraveh · #1 03/02/2007, 10:38 AM

Randy,
I read your article regarding pH-alkalinity relationship.
I am facing a persistent problem of low pH (7.73 night, 7.95 day) in face of high Alkalinity (~12 ). So my conclusion is that it must be CO2.
To prove that increased aeration will solve my problem I took a cup of water and agitated it with air outdoor. However the pH did not change.

Q1: Is it just sloppy experiment on my part or could the acidity be due to something other than CO2?
Q2: If I correct the pH to ~8.1 with very high levels of alkalinity- is there any downside to that (except for the risk of abiotic precipitation)?
Q3: Can you think of a better way to prove that increased aeration will solve my problem, before I invest in additional equipment?
Q4: is the diurnal variation of pH (~0.3 units) a strong enough proof that the acidity is due to CO2?

Q5 is switching to limewater likely to solve this magnitude of acidity?

Yehuda

newnano · #2 03/02/2007, 10:47 AM

Q5..dripping lime can help raise ph. but it depends on how much you are dripping or replacing. also using randys two part recipe with the "raising alk" recipe will help. i believe that is the recipe that involves baking the baking soda.

Rays · #3 03/02/2007, 10:53 AM

I had that problem on this forum a coupla months ago, and I'm happy to report via Randy, I resumed dripping kalk. My params are as stable as ever. My ph is 8.3 by end of day, and remains at 8.0 overnite. My alk has dropped to a steady 9.8, I may up it slightly, now that I have that luxury.

Oh, and I use Randy's two part as needed.

yraveh · #4 03/02/2007, 10:54 AM

Thanks for your help!
I apologize, I was not clear enough in Q5.
I know it will help but I am not sure if to go ahead and invest in aeration equipment. I did not get hold of limewater here is south Florida yet. I wonder if a switch to limewater alone is likely to solve an acidity problem of this magnitude. I currently use B-ionic

yraveh · #5 03/02/2007, 10:57 AM

Rays,
what were your pH readings before the switch to limewater?

Rays · #6 03/02/2007, 10:57 AM

I live in the northeast, and even opened the window in the fishroom in December, the difference was negligible at best.

Randy Holmes-Farley · #7 03/02/2007, 12:46 PM

yraveh:

How much water did you aerate for how long?

One reason to do the outside test, where pH should rise, is to determine if the pH measurement might be inaccurate.

How are you measuring pH?

Rays · #8 03/02/2007, 01:57 PM

Quote:

Originally posted by yraveh
Rays,
what were your pH readings before the switch to limewater?

Low to mid 7's, couldn't budge above 7.9.

Randy Holmes-Farley · #9 03/03/2007, 09:47 AM

Assuming that pH measurement is accurate, low to mid 7's represents extreme carbon dioxide elevation, so I'm not surprised the limewater couldn't get it above 7.9.

fish2morow · #10 03/03/2007, 09:58 AM

What are your mag levels?

kensilvey · #11 03/14/2007, 10:19 AM

I to have a low ph problem, ph= 7.9 night and 8.0 day Mg= 1200 Ca=400 Alk=4 meq temp=78-80 I to tried aerating outdoors with a .05 increase I also attached a tube with outside air to my protien skimmer air input and believe it or not ph went down .1 outside temps around 25 degrees Ferh. a bit cold but the tank temp did not seem to change. I use Aqua controller 2 with ph,orp and temp probes and have calibrated, have even checked with borax and temp for ph.