Quick GFO Alk question

reefinatl · Jul 9, 2021

When GFO is added and drives down Alk would proper baking soda dose be the appropriate course of action?

I've been using all for reef and holding steady at 8.5. The GFO knocked alk down and I don't know if I trust my CA test. I don't think GFO affects CA so I feel baking soda not AFR would be the appropriate thing to bump with.

Hincapiej4 · Jul 9, 2021

You could dose something to help the alk.

I haven't noticed my alk lowering with gfo oddly...but I also already have afr and an alk supplement running on trident dosing

Randy Holmes-Farley · Jul 9, 2021

reefinatl said:
When GFO is added and drives down Alk would proper baking soda dose be the appropriate course of action?

I've been using all for reef and holding steady at 8.5. The GFO knocked alk down and I don't know if I trust my CA test. I don't think GFO affects CA so I feel baking soda not AFR would be the appropriate thing to bump with.

GFO may reduce alk in some circumstances by inducing the precipitation of calcium carbonate on it or downstream of it.

It likely does deplete calcium, but the effect is too small to readily detect by kit.

In general, i don't think it matters how you replace the alk, and in many cases, it is an unnoticeably small effect anyway.

reefinatl · Jul 9, 2021

Randy Holmes-Farley said:
GFO may reduce alk in some circumstances by inducing the precipitation of calcium carbonate on it or downstream of it.

It likely does deplete calcium, but the effect is too small to readily detect by kit.

In general, i don't think it matters how you replace the alk, and in many cases, it is an unnoticeably small effect anyway.

I believe it drove mine down by 0.75 dkh with a bit over half a cup added. I'll use some baking soda to knock it back up. Thanks.