RO/DI for your CA Reactor??

[Gordoe]

Well it started in another post, and I didn't want to take away from Darren's CA Reactor.
So lets ask again..

Is it better to use RO/DI for your CA Reactor or to take a loop out of your sump?

If we keep our water at ph 8.2-8.4 and we want to get it to a ph of 6 for a CA reactor. Wouldn't it be better to use RO/DI??

RO/DI should have a ph of about 7, hence less co2 to get it to a ph of 6..

Just my take, anyone with REAL knowledge as opposed to my guess??

Gord

[reefburnaby]

Hi,

There isn't anything wrong with using RO water with a CA reactor. The problem is that it would have similar calcium replenshing rates as a kalk dripper or a kalk reactor would have. On the rare occasion, both system may not be able to replenish calcium fast enough because they are based on dripping in super saturated calcium solution at the rate of evaporation. If you evaporation rate is low, then calcium addition will also be low. In this situation, I would use a kalk reactor. It provides similar performance and it is cheaper (no CO2 equipment).

Where do they differ ? Calcium reactor has low pH effluent and kalk has high pH effluent.

The important thing to note that it is not the pH that is important. Rather it is the CO2 content in the water. The calcium reactor does the following (left side are the inputs <=> right side are the products) :

CO2(g) + H2O(l) + Ca(CO3)2 <=> 2HCO3(aq) + Ca++(aq) + CO3-(aq)

CO2 = CO2 gas.
H2O = water
Ca(C03)2 = Calcium Carbonate (reactor media)
HCO3 = Bicarbonate (buffer)
Ca++ = Calcium
CO3- = Carbonate (buffer)

So, this reaction not only produces calcium in the solution, but it buffers the water. This is why we usually use CO2 in calcium reactor.

Hope that helps.

- Victor.

[ 11 January 2002: Message edited by: reefburnaby ]

[ 11 January 2002: Message edited by: reefburnaby ]

[DJ88]

Gord,

That was the mistake I mentioned in my Ca reactor post. I am also making a Kalk stirrer and was doing the drawings at the same time.. images/smiles/icon_smile.gif

I don't run RO/DI into my reactor. I run water from the tank.

HTH...