why is my pH low?

[rahorman]

I've had my 34 gallon RSM for about 4 1/2 months now, and the pH has always been a little low. I've been using RO/DI. I just tested with both the API, and a new calibrated electronic meter I just got, pH was reading 7.8 / 7.9. I also checked my top off water (RO/DI) and it was around 7.7. Alkalinity is at 8, but I added some Kent marine DKH super buffer yesterday. I know 7.8 / 7.9 is too low, why is it so low? Is it bc I'm using RO/DI? Should I just keep adding buffer until it goes up to a safe level?

[dsn112]

Chasing PH is a terrible idea. 7.8 is fine and many peoples tank thrive with various PH levels. If your alk calcium and mag are good then your good!

 

Mine runs around 7.9-8.0 and my corals are loving my tank. Even have some zoos that a friend claimed was dead thriving in my tank.

 

Just chill and don't buffer anything

[rahorman]

Hmmm ok, I will stop dosing then...I gotta check my calcium levels now!

[kv2wr1]

Chasing PH is a terrible idea. 7.8 is fine and many peoples tank thrive with various PH levels. If your alk calcium and mag are good then your good!

 

Mine runs around 7.9-8.0 and my corals are loving my tank. Even have some zoos that a friend claimed was dead thriving in my tank.

 

Just chill and don't buffer anything

 

 

+1 Your PH will change throught the day and seasons. Try taking a reading right before your lights turn off. It should be the highest then.

[rahorman]

I did test before lights went off today and it was still under 8. Why would pH change thru seasons?

[kv2wr1]

I think it's more in nature than a home aquarium. Here is a good article on PH.

 

http://reefkeeping.com/issues/2005-03/rhf/index.php#6

[Phixion]

7.9 is fine. It's just at the low end of the spectrum, but it's not bad. I'd also suggest you stop chasing pH, that's a recipe for disater to be honest.

 

And FYI, RO/DI pH is low to begin with, like around 7.0 so don't worry about that, adding to your S/W will quickly match it to the tank.

[Mr. Fosi]

Are you using API to test your alk as well?

[fishguy84]

What helps me maintain a slightly higher (And stable PH) is a refugium with 24-hour lights. I am against buffers because I aim to do things as natural as possible.

 

Granted I am taking a reef and putting it in a glass box but you know what I mean.

[rahorman]

Yes, API to test my alk...I'm def going to stop using this buffer, I used it two days in a row..but no more..It hasn't even real raised my pH at all...I just tested again and i was getting a reading of 7.7. I'm using this 40$ electronic probe meter I bough. I calibrated it with fluid to 7.01...so I really have no idea whats going on

[rahorman]

This is the pH meter I bought:

 

http://www.drillspot.com/products/78218/Ha...KER_1_PH_Tester

 

I just did an API test and it was reading 8.2 ...to 7.6 from this electronic tester...I'm reading now that I should be using something that can be calibrated twice? That and this one needs to be stored in a solution...Is it possible that bc of this the 7.6 reading is not accurate?

[B16Drag]

I've used the Aquacontroller pH probe in the past, and you have to calibrate it to 7.0 and then to 10.0 to make sure that its accurate. Not exactly sure which pH probe you have.

 

A pH of 7.9 is fine. Mine in the past has even dipped down to 7.8 and most definitely fluctuates throughout the day and season. Usually worse during the winter time because people usually have their windows closed, and there is excess CO2 in the house therefore causing a drop in pH.

[rahorman]

Yea I just don't think I'm getting accurate readings from this meter then, since it is only calibrated once to 7.01. But everything looks healthy so I think I'm just being a little too cautious

[Phixion]

Sounds like it's not reading acurately for you. Any decent pH meter/probe should calibrate to BOTH 7.0 and 10.0 pH solution.

 

BTW, I have that same Hanna Checker model pH tester and maybe the probe on mine is bad (someone gave it to me used) because I can't get it to settle down when adjusting first to 7.0 pH solution. =/ Also, that meter you DO calibrate to two different solutions, look at the adjustment screws at the top. One is for low (7.0) and the other is for high (10.0). Adjust it properly to both and you should be good for go! Just read the directions on it for which screw is for which pH reading.

 

As for storing, you're supposed to put a tiny bit of pH 4.0 solution for storage in the cap. Annoying, but any probe requires this to work properly. Like the reviewer on the site said, it's ashame they don't tell you what if any solutions you'll need... =/ Your LFS or even any hydroponics store/shop should carry the necessary pH solutions. Good luck!!

[Mr. Fosi]

2-point calibration, as others have suggested.

 

Also, mix up some alk additive of your own and see how it goes.

[rahorman]

Ahh , did not know that ... thanks

[AZDesertRat]

Trying to measure the pH of RO/DI is pointless, there are not enough ions to measure accurately. It will be somewhat neutral but readings are influenced by things like CO2, dust, air movement etc. Don't put much stock in the readings.