Chasing Numbers and confused...

[Dsnyguy75]

Okay, So I'm trying to keep my pH between 7.8 and 8.0. At night I am getting swings from 7.4 to 7.9. However, I am doing starting to do 2 part dosing to keep the all/mag/cal all up. I am testing all three everynight for the last week to measure what my tank is actually consuming to setup my dosing pumps. I am getting the following results:

Alk 7 dKh
Cal 500
Mag 1320

So I add the necessary alk 2 part per the BRS calculator in two parts at night and in the am. However I am still reading the same. I'm trying to understand Randy's article about what is actually consuming the alkalinity but I don't understand. I have the following in my tank:

Fire and Ice Zoas
GSP
Walking Anthelia
Torch
Tiger Paws Zoas?

Nothing is larger than a golf ball or a dime. So I don't see how it could be consuming that much without a dip in the other numbers as well.

HELP?

 

[Randy Holmes-Farley Verified Community Expert]

How are you measuring pH? I suspect pH 7.4 is not accurate.

How much alk, in dKH, are you dosing each day?

 

[Dsnyguy75]

I am measuring pH via 2 methods. Using API test kit and with monthly calibrated RK pH probe using 7.o/10.0 solutions.

Alk I'm currently dosing 3.5mL every 24 hours it seems. I stopped after 3 days because I don't want to throw the tank into wack.

 

[Robink]

I believe that with the corals you currently have you could keep up with their demands with weekly water changes.
Don't worry about your ph. How long has your tank been set up?
Randy's here, he's the expert.

 

[Dsnyguy75]

6 months. Due to money flow, we've taken the slow route to get the tank up and running. Added just live rock initially. Added a couple of clowns. and Just added some more fish/corals last month.

 

[Randy Holmes-Farley Verified Community Expert]

I am measuring pH via 2 methods. Using API test kit and with monthly calibrated RK pH probe using 7.o/10.0 solutions.

Alk I'm currently dosing 3.5mL every 24 hours it seems. I stopped after 3 days because I don't want to throw the tank into wack.

I’d recalibrate. pH 7.4 is not likely. Kits aren’t worth using.

 

[Robink]

How often are you doing water changes?

 

[Randy Holmes-Farley Verified Community Expert]

You need to determine the alk dose in dKH per day to be able to say why you may not be seeing an effect.

 

[WWIII]

3.5ml of alk solution per day isn't very much, how big is the tank? Most likely you don't need to dose anything at this point and just do waterchanges. What salt are you using?

 

[Randy Holmes-Farley Verified Community Expert]

You need the tank volume to do that calculation with an online calculator, and I don’t see the volume.

 

[Dsnyguy75]

I'm calculating using 55 gal volume. I have a 55g display and 20gal sump. with live rock in display and the fact the sump baffles are only 6 inches high, I think I'm pretty close in volume.

 

[Dsnyguy75]

How do I determine the Alk dose in dKh per day? Isn't that what the BRS calculator does?

 

[WWIII]

So you are seeing the alk drop from one day to the next? What test kit do you use for alk? What dkh are you shooting for? What I do to figure out consumption of alk is measure in the morning right before lights come on and then again right before lights go out at night. I do this every day and adjust until I get the tank where I want it. Once I get the dkh steady I leave the doser set and test once per week.

 

[Dsnyguy75]

I'm using the api currently. Ordered the hanna. I'm shooting for 9-10 dKh.

 

[WWIII]

At that tank volume, using brs 2 part and dosing 3.5ml per day you will only be dosing .1 dkh per day. (Roughly, I think). What salt are you using? Different salts, even same salts different batches, have different alkalinity dkh.

 

[Dsnyguy75]

I'm using IO.

 

[WWIII]

Using the online calculator it looks like to go from 7dkh to 8dkh at 55 gallons you would need to dose 39.2ml of brs soda ash. Is that what you came up with?

 

[WWIII]

I'm using IO.

I think 7 dkh is pretty typical for IO, but you can definitely raise it. Just gotta get the tank where you want it and then monitor to see how much the tank is consuming daily to keep it there

 

[Dsnyguy75]

Yes. I've been dosing 35mL/day.

 

[wattson]

did not see the salinity level of your tank in prior replies.