Best dosing techniques

[Reef Pilot]

I dose Ca for 2 or 3 hours during the day, and Alk for 3 or 4 hours overnight. I manually dose Mg with my water change every 3 weeks.

I've had to increase the dose concentrations quite significantly over the last several months, esp the Alk. And now have to dose Mg as well, as that was getting pretty low now, too. I am sure it is all due to my SPS growth, as it is getting really crazy lately.

[mark]

I'm using a 2 head pump for Ca and Alk, dosing once an hour into my sump with the drip lines separated by about 12". Mg manually followng RHF instructions for when Ca/Alk jugs are done.

[Sunee]

GHL doser randomly doses Alk, Ca and Mg (7 times per day).

[jason604]

I heard dosing alk is better during lights off due to ph fluctuation?

[Sunee]

I have not researched this but I would think dosing Alk and Ca in small amounts alternately throughout the day would produce smaller swings in both pH and Alk and Ca levels than dosing all your Alk at night and all your Ca during the day. Maybe someone who has looked into this could chime in.

[Reef Pilot]

I think the fears of alk swings are overblown. Of course, you want to be reasonably consistent. I keep mine close to 8, but it ranges from 7 - 9 (as high as 10 sometimes) with water changes and as I adjust my dosing. My SPS growth and color have certainly not been affected.

And yes, better to dose alk at night to keep your pH up. And my Ca has been all over the place, too, from 380 - 480. It varies the most for me.

What I have seen, though, is the impact of higher phosphates. That seems to have a pretty immediate and lasting effect, and takes a while to get back to good growth and color.

If you want the best growth and color for your SPS, get the phosphates down to zero (as measured by the Hanna digital checker, not the color test kits). Plus your algae disappears then, too, so it much less work to keep your tank looking good. And don't forget your MB7.

[mark]

^ am I missing something, is there a linkage between dosing and phosphates?