question on Calcium reactor effluent

[oligotrophic]

Hello everyone,

I'm considering to reduce the pH of Calcium reactor effluent by running it inside a chamber supplied with vigorous bubbles from an airstone, would this process result in the reduction of soluble Calcium ions beneficial to the reef?

Thanks in advance

[Boomer]

Will there be anything inside the chamber. Dual reactor reactors more or less use another chamber with the same media to absorb the CO2 and produce less pH problems.

If just bubbles in that chamber it may do nothing unless that air is degassed out of that chamber to remove CO2. If so, under the right conditions, the Ca++ may leave solution and precip out in that chamber, as there is little CO2 to keep in in solution..

[oligotrophic]

Thanks Boomer for the reply


1. there will be nothing inside that degassing chamber except for an airstone, the chamber will be elongated for maximum exposure to bubbles. Effluent comes from a dual chamber reactor

2. the degassing chamber will have an outlet for both air and CO2 to exit. So it sounds like if too much bubbling I would end up with Calcium precipitate ... that sounds not so good. Perhaps I might have to skip the degass chamber ? I'm currently at the design stage so I could change this. Perhaps a workaround would be to utilize an adjustable speed air pump and a transparent chamber, so that if I notice precipitate I would reduce the amount of bubbles?

[Boomer]

Ok let me know what happens. Low pH in single stage reactors has long been an issue form many due to excess CO2

[Gudwyn]

I would recommend mixing the effluent with tank water before degassing. You are less likely to precipitate.

This isn't as hard as it sounds. Right now I have a GFO reactor fed by 1/2" tubing at ~40gph of tank water. At the place where the tubing enters the reactor, I have a tee and a vertical piece of 1/2" tubing (maybe 6" long). My effluent drips into this tubing and mixes with the tank water before going thru the GFO media.

You could do the same thing for your off-gassing chamber. If you mix 4 parts tank water with 1 part effluent before offgassing, it's going to be a lot less likely to precipitate.

[oligotrophic]

Thanks Gudwyn, I'll try to drip some tank water into this chamber.

cheers

[Boomer]

Gud

That sounds like a good idea and worth a try.

[oligotrophic]

would adding a third chamber cause precipitation of Ca++ due to higher pH ?

i remember seeing a calcium reactor where a narrow, elongated final chamber (with calcium carbonate media) is used to increase pH