Phoshate, Kalkwasser and Cyano - Could Kalk be fueling my Cyano Problem

[Dan_P]

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 (exact mechanism is unclear) 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?

A possible useful rule of thumb is that a high density population of microorganisms need a high concentration of food to exist. A dense cyanobacteria film is going to need a much larger amount of inorganic nitrogen than phosphate to exist. Your aquarium does not sound like it is depleted of phosphate. Inorganic nitrogen could be fueling the growth.

Since the sand seems to be providing a high concentration of food and not the rocks, I would think it is the large availability of nitrogen from the sand processing organic nitrogen, protein for example. Rocks likely cannot process organic nitrogen as well as sands.

 

[arafas]

I do not think we have a good handle on why coralline thrives in some tanks and not others, but I have always thought tht higher pH, lower phosphate (say, 0.03-0.05 ppm) and higher magnesium (say, 1400 ppm) are likely to be desirable.

OK, I understand now. Yes all those paremeters within what you mentioned but coralline almost not there. This answer my questions thanks again for the help. One last question I promise . So I currently run 2 part esv. If I wanted to run kalkwasser and let's say 2 part for cheaper approach. How one person goes about adding kalk without having crazy swings, I guess how much kalk solution do you add and how much 2 part to cut back. Essentially keeping parameters stable.

 

[Lasse]

IMO - to increase the precipitation of phosphorous into the gravel will take PO4 from the water column and concentrate it in the sand - in my world it will make the cyan problem worse

Sincerely Lasse

 

[Randy Holmes-Farley]

OK, I understand now. Yes all those paremeters within what you mentioned but coralline almost not there. This answer my questions thanks again for the help. One last question I promise . So I currently run 2 part esv. If I wanted to run kalkwasser and let's say 2 part for cheaper approach. How one person goes about adding kalk without having crazy swings, I guess how much kalk solution do you add and how much 2 part to cut back. Essentially keeping parameters stable.

You can use this calculator to see how much limewater/kalkwasser is equivalent to how much of different brands of two parts:

Reef Chemistry Calculator

 

[arafas]

You can use this calculator to see how much limewater/kalkwasser is equivalent to how much of different brands of two parts:

Reef Chemistry Calculator

Appreciate it @Randy Holmes-Farley

 

[Randy Holmes-Farley]

Appreciate it @Randy Holmes-Farley

You're welcome.

Happy reefing.