Zero Alk, Cal and Mag usage

[miller75]

Our Red Sea 425XL has been up for about 18 months now after a restart, its an LPS tank (except one Kenya tree and a couple zowa). Since we started we have never had any Alk, Cal and Mag usage, everything looks happy but nothing grows.

I have just done tests and they are almost identical to 5 days ago

10th July
Alk - 153 (8.554 dKH)
Mag - 1440
Cal - 440
Nitrate - 15.7
Phosphate - 0.09

Today
Alk - 152 (8.498 dKH)
Mag - 1440
Cal - 440
Nitrate - 16.9
Phosphate - 0.08

I also have no Coralline algae in the tank, the only things I am dosing are Phosphate and Tropic Marin Pro Coral A & K

Does anyone have any idea what could be going on?

Thanks

 

[Randy Holmes-Farley Verified Community Expert]

Can you post a picture of the tank?

Not sure there is any problem, but have you ever tried to dose a trace element mix?

Do you do water changes?

 

[miller75]

I will get a photo up when I get home, I am dosing 3ml per day of Tropic Marin Pro A & K elements. I do about 75l (About 18%) water changes every 7 - 10 days using Tropic Marin Pro Reef Salt

 

[miller75]

Not a very good photo but here you go

 

[Randy Holmes-Farley Verified Community Expert]

I would expect pretty low demand in that tank, with just a few corals and little coralline in a large water volume.

I wouldn't worry about the apparent lack of demand.

 

[miller75]

Thanks Randy

 

[Lavey29]

I agree with the above and your weekly water changes replenish what is being used. As you add more corals, consumption should increase proportionally especially if SPS and LPS are added.