Help with low Kh

[Phill]

Hi guys, some experience and help needed with my chemistry please, I've kept steady params for a year now except a spike in nitrates which is now over, however with my coral stock ever increasing things are starting to change and I have also started to move to fortnightly water changes instead of weekly in a view to keeping things stable and reduce salt cost,
just done full tests my ph and Kh ar a little low, I'm due a water change this Sunday so will test again on Monday evening but want to stock up this weekend on what I need to raise it, what do you recommend? Do I just need baking soda? My full tests can be seen in signature

[Aaron]

Bicarbonate of Soda is what you want, cheap and easy.

[Phill]

Bicarbonate of Soda is what you want, cheap and easy.

Ok cheers what's best way, mix with a little Ro then add with with water change I assume?
how much would be a good starting point its a 300l system?

[Aaron]

Use an alkalinity calculator to calculate how many grams for your volume of water to raise it by 1dKH, mix in some RO and drip it into the tank/sump. Surely a WC will bring your dKH up on Sunday so just buffer with Bicarb between now and Sunday?

[Phill]

Yes sounds best, cheers pal much appreciated

[Aaron]

You're welcome.

[Phill]

Ok just checked on a online calculator says I'll need 4.6 tea spoons to reach alk of 9???
seems a lot?
Think maybe 1 tea spoon at a time?

[Aaron]

For 300L to raise it by 1 dKH it's 9 grams. Raise it by 1dKH each day or you could upset your inhabitants with a big swing.

[Phill]

Ok thanks again

[shelbygt]

When i raise mine i add 1 teaspoon added to warmish R.O water as i fine it mixes in better and drip into the tank over the course of the day...