Phosphate, Kalkwasser and Cyano

[Reefdom]

I've been thinking, mainly due to a cyano problem on my sand bed and a little on my rocks.

We know Kalk precipitates out phosphate into Calcium Phosphate and renders it inaccessible to corals, possibly algae and maybe cyano???

Some will be removed by the skimmer but some will circulate and settle out in the substrate.

Does cyano have the ability to pull the phosphate out of calcium phosphate? If so it could have the monopoly on phosphates, allowing very easy proliferation.

I have little algae, have done for a good few weeks now,high ph, which may help phosphate precipitation, and low residual phosphate in the water, yet cyano seems to have no problem spreading.

Coral growth is good, colours are good.

Any thoughts from those with a better understanding than myself?

[G.Alexander]

The bound PO4 can be accessed from algae directly, this is why systems which have used kalkwasser in the past do observe green hair algae growth even if PO4 is not detectable. The algae do pick up the PO4 directly from the substrate, not sure about cyanos.

G.Alexander

[Reefdom]

thank you. I have removed my kalkwasser stirrer as a test to see the impact on algae and cyano growth.

I will be monitoring nutrient levels this week to see if po4 raises or stays at zero.