Addressing low alk and low nutrients

[Spkarim]

Hi, I’m wondering how to address low alk and possibly low nutrients.

I have a 1+ year old 40g SPS/LPS/clam tank with 2 clowns, cardinal, wrasse, and fire fish. It has a 20g sump with some mangroves, using ATO with kalk that I think is saturated. I stopped skimmer and GFO several weeks ago after seeing nutrients low.

I test rarely but tonight was surprised to find alk low. All tests salifert except pH (api)

alk 5.7
Ca 450
pH 8.2
nitrates - undetectable
Phosphates - undetectable.
76 deg, 1.025

I am trying extra feeding to bring up nutrients, but do have algae in tank.

my next step is to try to bring up alk, probably by adding baking soda.

what do you think?

thanks

 

[watty21]

What nutrients do you think are low? Consistent water changes might handle what you're thinking about.

The alk is pretty low. Do you normally just do water changes and not dose? If you're going to start dosing, do it slowly! You don't want to jump from 5.7 to 8 in one day. Spread it out over a week at least.

 

[Spkarim]

I’m not sure if I should start dosing nitrates and phosphates.

My water changes are about 20% every 2-3 weeks

I don’t add anything else to the tank but the kalk through the ATO.

 

[ShepherdReefer]

What type of salt mix do you use?

 

[Spkarim]

What type of salt mix do you use?

I’m using IO reef crystals