Please help!!!!! Alkalinity too high. What to do?!

[JuliaRuss]

Hello, saltwater chemistry gurus:

I am having trouble with super high alkalinity:

-my water source: 4.5 dKH
-freshly made batch of saltwater, using instant ocean (regular): 13 dKH (already too high)

current problem: alkalinity too high. Can’t hold pH steady (keeps going lower). Calcium and magnesium keeps dropping.

Equipment: Fluval Evo 13.5 G. Cycled since January. Corals only.

salinity: 1.025
Temp: 76F
PH: 8.0 (I just added some baking soda)
NH3: 0
NO2: 0
NO3: 0
PO4: 0.25
Mg: 1020 (I just added some Mg supplement)
Ca: 325 (I just added some Ca supplement)
Kh: 15 (!!!!!!!!!!!)

My eventual goal is to add two clownfish, an anemone, and a small CUC.

Any insights will be super appreciated!!!! Thank you!

 

[arking_mark]

Baking soda can greatly raise Alk and shouldn't be used to increase pH.

 

[arking_mark]

https://www.reef2reef.com/threads/the-11-commandments-of-reef-keeping.817592/
Most problems can be mitigated with larger water changes and GAC

I recommend you do some large water changes with fresh ASW.

 

[arking_mark]

Also, 13dKH is high for IO ASW. Most find it 11dKHish. I would suspect your observed measurements. What are you using to get your Alk measurements?

 

[dedragon]

what source of water are you using? is it rodi water because it shouldnt have any alkalinity (i think)

 

[arking_mark]

Also, with a smaller tank like the Fluval 13.5, I would go with larger water changes rather than dosing. Your measurements may be off and quality salt is rarely off.

 

[dedragon]

are you using an adequate amount of aragonite sand in the tank or live rock? that usually helps with ph swings for me. If pH is dipping opening a window and also directing flow towards surface to help surface water agitation can help with o2 and ph problems.

 

[Randy Holmes-Farley Verified Community Expert]

are you using an adequate amount of aragonite sand in the tank or live rock? that usually helps with ph swings for me. If pH is dipping opening a window and also directing flow towards surface to help surface water agitation can help with o2 and ph problems.

I do not think the aragonite is helping with pH swings, unless you are talking about well down into the 7's. It does not dissolve at any pH above 7.8 in seawater.

 

[Randy Holmes-Farley Verified Community Expert]

-my water source: 4.5 dKH

As folks noted, that may be the issue.

What is that water?

You add it to make new salt water and for top off?

There is 0 alkalinity in pure water.