PH and Alkalinity

Rookie_Reefer · Mar 4, 2014

My reef tank has a PH of 7.4 so I was told to add some buffer. I started reading buffer instructions. It says
1) For reef tank the PH has to be between 8 and 8.3 and Alkalinity 2.9 to 4.0 meq/l.
2) For fish only tank PH has to be 8 to 8.3 and alkalinity 2.9 to 4.0 meq/l.

For the life of me i don't understand how the same ph range can have two different Alkalinity. Please enlighten. I was about to put buffer in the tank but stopped becuase I don't have a way to measure alkalinity.

wuuzzzuuppp · Mar 4, 2014

Here' a link that helped me understand the stuff a little better

Aquarium pH Control For Dummies - Saltwater Aquarium pH and Alkalinity Simplified

wuuzzzuuppp · Mar 4, 2014

You should get an alkalinity test along with calcium and magnesium if you dont already. They all go hand and hand along with your ph

Rookie_Reefer · Mar 4, 2014

wuuzzzuuppp said:
You should get an alkalinity test along with calcium and magnesium if you dont already. They all go hand and hand along with your ph

Thanks. It still doesn't answer my questions as to how a PH level of 8 -8.3 can have different alkalinity.

wuuzzzuuppp · Mar 4, 2014

I know PH can change with the higher the O2 in the water. It will be higher at night than in the morning. Sorry I'm not a pro at it. Trying to help you figure it out though. Soon enough a pro will get in here and square us away lol. Here's another article that kinda explains why it can be different.

Alkalinity and PH: How They Pertain to Saltwater Aquariums - Yahoo Voices - voices.yahoo.com

wuuzzzuuppp · Mar 4, 2014

wuuzzzuuppp said:
It will be higher at night than in the morning.

meaning at night just before your lights go out

wuuzzzuuppp · Mar 4, 2014

Here's another good on The Urban Legend Regarding PH and Alkalinity Being One and the Same, Laid to Rest - Yahoo Voices - voices.yahoo.com

watdachuck · Mar 4, 2014

Alkalinity is the buffering capacity of your water. A bad situation would be of you had low Alk and low PH, i.e. below 7.80, not 8.00. Below 7.80 is where corals lose the ability to grow their skeletal structure and in some cases it begins to disolve. If you have a lower PH with stable Alk your aquarium should be in a good position to maintain a safe level. Adding too much buffer to achieve the "ideal zone" can be dangerous as these buffers also increase Alk. If you shoot for the "ideal" zone you could over shoot a safe Alk level which will cause as much damage as acidic PH. I never freak unless my PH falls below 7.85 in my SPS dominated tank. I also don't use buffers ever but that's my own opinion as often something else is driving the PH down.

Rookie_Reefer · Mar 5, 2014

Thanks for the info, good info. Ph in my tank is 7.4 and I got it from my cousis and he said its been that way for a year. I don't know the alkalinity in it. I used buffer few days ago to raise PH without realizing that it could screw up alkalinity so i stopped. We moved this tank over the weekend to my place. May be i need to replace 20% of the water and see if any changes to PH.