pH issue - need some help please

[02tts]

ok so here is an update...I let the pH drop to see how low it would go and it went down to 7.95 and stayed there...this is also 24 hours AFTER having (2) koralia magnun 6's put in, one on each end, pointing down on a 45 degree angle so as to stir the water on the bottom and bring it up for a better gas exchange...and of course, as predicted, no change in pH.

so now the tank has a constant movement of 5600GPH with no change at all to the pH, and this is with the top surface being agressively agitated by the returns...so, i've pretty much given up, nothing I try brings the pH up naturally...

so I've resorted to dosing with kalkwasser, this allows me to maintain alkalinity where it's at, 4meq/l, a calcium of 420-450 for coraline algea growth (as I a have a fish only tank) and a steady pH....right now my pH is at 8.05, we'll see if I can get it to 8.2 or 8.3 with the dosing...should be able to given kalk mix has a pH of around 12.5

i"m open to any other thoughts out there on this pH issue....surprised no one else has ever come across something like this.

 

[cmor1701d]

When mixing a fresh batch are you mixing at temp overnight (24 hours preferably) with a powerhead and then testing? It seems you are using it within hours of mixing and it drops from a fresh mix pH of 8.3 to an aerated mix pH of 8.1. Is that correct?

How old is your house? Is it tightly sealed? Is there a window in the room that the tank is in that you can crack open a bit? Just wondering if you have a tight house with a minor CO2 problem.

BTW I think it was Tropic Marin that I stopped using due to low pH in the mix after 24 hours. I had the same issue with Kent and they confirmed it, and sent me some turbo calc and buffer when I refused another bucket of salt from them.

 

[SpeedEuphoria]

When mixing a fresh batch are you mixing at temp overnight (24 hours preferably) with a powerhead and then testing? It seems you are using it within hours of mixing and it drops from a fresh mix pH of 8.3 to an aerated mix pH of 8.1. Is that correct?

Thats what I was implying or inquiring about in my post.

The test mention in the 1st post was an 8hr test. As anything multiple tests are in order to confirm.

 

[02tts]

if I let the fresh mix sit out for 24 hours, aerated with a pump: 1200GPH pump circulating with two returns at 3/4" (so high pressure since the pump outlet is 1") for 24 hours, the pH only drops to 8.22 to 8.24, from 8.3 or 8.4 (depending on how much salt I put in).

house is 2003 constrcution but no CO2 problem is present given the simple water test using tank water left inside and outside the house, whereby the pH only inscreses by .02 if left out there for 12-24 hours vs. inside.

now I just noticed something interesting...my amonnia is 0, my nitrates are 7-8 (digitally metered), 10 on the chemical, but my NITRITES, interestingly enough, are 0.5 - they've always been zero, but I just measured them and they're high...so i"m guessing there's some cycling going on here and the nitrification process is keeping my pH down due to the acids introduced....thoughts...

as to why my nitrites are high, I have no idea, as I'm removed all sand and replaced with aragonite DRY sand (washed before put in), of course, I did not use RO/DI for this and while my city water contains little to no nitrites maybe this is where it's coming from...and I removed all live rock, so maybe this caused a small cycle in the tank...thoughts....

my nitrates could be registering low also because I have nitrate sponge media so it may be sucking up most of the nitrates that would be expelled because of the nitrification process...

thoughts....(but I'm thinking my nitritates are affecting my pH at this point, which would make sense as to why I can't raise it and keep it raised).

 

[cmor1701d]

The beneficial bacteria that break down ammonia to nitrite and nitrite to nitrate colonize the rock and sand surfaces. Removing those removed your biological filter. That is probably why you are seeing a mini-cycle.

Again, a pH of 8.1 is fine. I'm slowly trying to get mine back to that level. My pH meter was reading high. I removed the probe, cleaned it and then calibrated it over the weekend. Now it's reading under 8.0 or just at that level before lights out.