ALK difference between Tank and Change water

[Jason McKenzie]

Ok so over the last couple of days I have been able to raise my Alk to 10.4dKH.
But I need some carification. during this time I have not been adding Calcium suppliments. But last night after an Alk test I tested for CA it measured 430.
I know if you have extermly low Alk, CA will not be utilized by corals but was a dKH of 7 enough to stop the absorption of CA?

Jason

[karlas]

i dont think it would completely stop absorbing calc but also watch your ph alk has a major effect on stabalizing ph and that can drop a lot

[Wrassman]

[glow=Blue, 2, 90%]If you aren't adding Ca while you add Alk, then your Alk will not stay elevated. You really need a more "balanced" approach, with the addition of Alk, then Ca, then take a look at your pH to see if it is dropping (if it is, add a buffer), then look at your Alk again.

You have to keep it all balanced, though, or it won't stay at the high level you are trying to acheive.

Oh, also, you should be watching your Mg during this time. If you keep some Mg in there as well as Ca, it will help keep things balanced.

I hope this makes sense!! If not, let me know and I'll try to clarify. [/glow]