Alk dropping ?

[cjrudy]

Ok, I am officially confused, I started dosing Kalk in my ATO to increase my PH and keep my parameters steady. My tank is primarily SPS.


For some reason my Alk has been dropping, from 10 to 8 to 6 over the past week and a half.


Any suggestions ?


Salinity 1.026
PH 8.4
Temp 79-80
Phosphates 0
CA 480-500
Alk 6 (currently)

 

[ritter6788]

Are you dosing full strength kalk? How big is your tank?

 

[cjrudy]

90 gallon with a 30 gallon sump, started dosing 1tsp per 5gallons of RO/DI, now up to 4 tsp for 5 gallons RO/DI

 

[ritter6788]

Full strength kalk is 2 tsp. per 5 gal. You can increase your amount if needed. Kalk has limits so if you still can't maintain alk you can dose baking soda.

 

[Pappy]

What's your mag?

 

[dougers31]

Full strength kalk is 2 tsp. per 5 gal. You can increase your amount if needed. Kalk has limits so if you still can't maintain alk you can dose baking soda.

Huh. I thought it was 2 tsp. per gallon.

 

[kingb4c0]

Huh. I thought it was 2 tsp. per gallon.

Correct! 2 tsp per gallon of RO/DI water

 

[ritter6788]

Huh. I thought it was 2 tsp. per gallon.

Yep. Sorry. That came out of my head wrong.

 

[cjrudy]

Maybe I should test Mag before I increase my Kalk

 

[cjrudy]

Bought a Magnesium kit and retested everything

Mag 1440
Alk 5.7
CA 490
PH 8.3

 

[Pappy]

This is odd I thought for sure it would be a mag issue I'm stuck too sorry

 

[MBG75]

As you cal climbs high, it will push alk down.

Either start Dosing alk or back off the Kalk a bit

There is a fine balance you have to find between the 2

 

[WillKatt]

Have you tried a different test kit?

 

[cjrudy]

Yes these are brand new Salifert kits, and my CA has been high for the past year

 

[Downbeach]

Kalkwasser isn't really going to elevate your Ca and/or Alk, it will just help to maintain it. Go the the BRS home page and open the Reef Calculator, add your current conditions, and the additive, and it will tell you how much to dose. If you don't have any type of a two part solution simply use baking soda.

 

[WillKatt]

Read this article by RHF. It sounds like Kalk by itself isn't keeping up in your system and you need more of a balanced additive. Perhaps you need to go to a two part balling method or a calcium. Reactor As RHF points out here that when mag and cal appear to be in check but alk is low the fact that calcium measures in an acceptable range is really only an illusion and you actually need more of both cal and alk.

To me this would suggest the Kalk isn't keeping up. Could it be that something else changed that's causing the alk to precipitate out of solution?

When Do Calcium and Alkalinity Demand Not Exactly Balance? by Randy Holmes-Farley - Reefkeeping.com

 

[Badspstank]

something is swinging check mag maybe your cal

 

[cjrudy]

something is swinging check mag maybe your cal

Just posted my Ca and Mag readings

 

[Fieroguy19]

Kalkwasser isn't really going to elevate your Ca and/or Alk, it will just help to maintain it. Go the the BRS home page and open the Reef Calculator, add your current conditions, and the additive, and it will tell you how much to dose. If you don't have any type of a two part solution simply use baking soda.

+1 You wont be able to raise your Alk with kalk very easily. Since your alk was dropping you need to raise the concentration of your kalk to 2tsp/gal. If your system is mostly SPS and growing well, it will be very difficult to keep your levels stable with kalk alone long term.

 

[cjrudy]

I spoke with my LFS last night who indicated he recently contacted Coralife about a large bad batch of salt he received, apparently with very low Alk readings, nearing 2 dkh.


We could not verify whether the salt I have from him was part of that batch. But I will be mixing up and testing a new batch of saltwater to check the Alk reading.