alk equation

[skratchiechan]

have an alk reading of 7 and if I combine alk at 10. what is the total dkh of the final alk?

[bnumair]

how much water are u changing? and total volume of tank?

[bnumair]

example if u did 10% water change with new water alk at 10dkh and current of 7dkh then you will end up with 7.3dkh after the water change of 10% .
WC% final alk
10 7.3
20 7.6
30 7.9
40 8.2
50 8.5
60 8.8
70 9.1
80 9.4
90 9.7
100 10

[skratchiechan]

I'm doing a 10gallon wc on a 150 gallons... I'm running bio pellets so I don't want to raise my alk more than 7-8 range.

so 10% = .3 raise in alk... what is the formula for that? tia

[bnumair]

formula is new salt alk(10) - current alk(7) = 3
3 x 10% = 0.3
3 x 20% = 0.6 so on so forth.

[Randy Holmes-Farley]

FWIW, just because you run pellets does not mean you need to keep alk in the 7-8 range.

IMO, that is only if you keep a ULNS system and have certain SPS corals. :)

[skratchiechan]

thanks bnu and randy!

[Randy Holmes-Farley]

:thumbsup:

Happy Reefing. :)

[tmz]

Even with sps and organic carbon dosing 9 to 10dkh works well, ime with PO4 <.04ppm and NO 3 around .2ppm.