Newbie Alkalinity Question

[shadynate]

Hey there, new reef keeper here. I had a question about alkalinity and pH. My pH was 7.9 and dKH 8.0. I wanted to raise both so I added 20mL RedSea foundation B to my 25g tank. The pH went up to about 8.6 and dKH 10.2. But after 2 days the pH has dropped to 8.0 and dKH to 9.0. I have no livestock in the tank, it is still cycling. Is there a better product to keep the alkalinity and pH stable? Such as seachem buffer? Am I using the wrong product? Or will it take dosing the tank daily with a product to keep dKH around 9-10? Any other threads already on this topic would be great or otherwise any advice on maintaining stable parameters. Thanks

 

[hoffmeyerz]

Your initial pH and alkalinity numbers don't seem that bad, especially since the tank is new and still cycling. I would suggest leaving it alone for now, let it complete cycling and settle in. Keep monitoring your params in the meantime, it will eventually tell you what it needs.
I've only been running my tank a little over a year, I'm sure some of the more long-term vets here can help too!
Good luck and welcome to the forum

 

[chipmunkofdoom2]

There are benefits to higher pH, but pH is difficult to control in reef aquaria. pH is almost entirely determined by the amount of CO2 in your water. To increase pH without raising alkalinity, you need to either decrease ambient CO2 levels in your home, or add an air source that's low in CO2 (outside air line, CO2 scrubber, etc).

You can get a pH boost if you also need to raise alkalinity. Supplements like limewater and sodium carbonate raise alkalinity and have a pH boosting effect. Hydroxide-based solutions in particular have a very powerful pH boosting effect. Unfortunately, the effect is short-lived in many cases. As soon as the CO2 begins working its way into your water from the surrounding air, the pH will simply drop again.

Further reading on the topic can be found here.

pH around 7.9 - 8 is fine. Don't mess with it. It's really tricky to get right, and you only realize the benefits if you're trying to maximize coral growth.

 

[shadynate]

Awesome that makes sense and makes me feel reassured. Thank you guys

 

[Spicy Reef]

Hey there, new reef keeper here. I had a question about alkalinity and pH. My pH was 7.9 and dKH 8.0. I wanted to raise both so I added 20mL RedSea foundation B to my 25g tank. The pH went up to about 8.6 and dKH 10.2. But after 2 days the pH has dropped to 8.0 and dKH to 9.0. I have no livestock in the tank, it is still cycling. Is there a better product to keep the alkalinity and pH stable? Such as seachem buffer? Am I using the wrong product? Or will it take dosing the tank daily with a product to keep dKH around 9-10? Any other threads already on this topic would be great or otherwise any advice on maintaining stable parameters. Thanks

I agree, let it ride out, settle in... then see what it needs. When coralline algae starts to kick in you'll see a big consumption of the big 3 as well. It was a good time for me to learn about balancing everything in the tank during the first year. Have fun, ur concerned about the right things

 

[Randy Holmes-Farley Verified Community Expert]

Hey there, new reef keeper here. I had a question about alkalinity and pH. My pH was 7.9 and dKH 8.0. I wanted to raise both so I added 20mL RedSea foundation B to my 25g tank. The pH went up to about 8.6 and dKH 10.2. But after 2 days the pH has dropped to 8.0 and dKH to 9.0. I have no livestock in the tank, it is still cycling. Is there a better product to keep the alkalinity and pH stable? Such as seachem buffer?

pH is not kept stable by any alk supplement. Don't be fooled by marketing claims.

pH is determined by the alkalinity in the water and the CO2 level. The daily pH swing is caused mostly by changes in CO2 caused by photosynthesis and respiration in the aquarium, but is also impacted by CO2 in your home air.