Maintain calcium through ro unit?

[crabbejoe]

I read somewhere that someone put an extra canister on their ro/di unit and filled it with crushed coral to maintain their calcium levels. They said it works similar to a calcium reactor because the low ph of the water coming out of the ro/di filter. Think there's any truth to that? I'd like to try it and test it out.

 

[wicked demon]

It could work on a small scale, but I wouldn't trust it to be your total source of Ca. To work really well you would need a LOT of arragonite in a large container and good exposure time. I think filling the bottom 1/4-1/3 of your fresh water resevoir and adding a power head with venturi aimed at the arragonite might boost Ca more signifigantly. I just use the clear water out of kalk slurry to make my salt mix.

 

[Bri Guy]

? this would be put on AFTER the DI resin right?

 

[crabbejoe]

I think so, yes.

 

[Jhildebrand]

it would be for sure or you wouldn't be happy...

 

[kevchem]

In a canister under flow it wouldn't dissolve fast enough. Put it in the bottom of your holding tank though and then you might have something.

Kevin

 

[110reef]

Actually, RO/DI water is quite corrosive. It will eat up metal piping, even stainless steel - which is why everything associated with it is typically plastic. Water wants to contain ions, and will suck them up wherever it can. So, it makes sense (to me) that passing it through a bed of coral it will probably pick up a good bit of Ca, Mg, CO3. An interesting thought, should try it and see!

 

[Bri Guy]

That would make some good ATO water, not so much for mixing batches of SW though.

Neat concept, should post this in the Advanced Forum on RC and see what happens...

 

[crabbejoe]

Good idea! And I got one heck of a good answer!

Maintain calcium through your RO unit? - Reef Central Online Community

 

[Bri Guy]

I see what Randy is saying about it working only to a point.

As corrosive as RO/DI water may be, it is only that way in its pure state, as soon as something is added, it will stop pulling more.

So the original idea of having it inline would work better than in the holding tank. But neither will work to the point of you seeing any savings.

His idea of calcium carbonate in fresh water. Its like adding Purple UP or Kents Liquid reactor to your RO water. It would hold more than if you put it in SW, you can then use this as a top off. But it holds less than kalk water. And kalk water doesn't have nearly as much in it as two part.

So you see there is just too little of an amount to even go through the hassle.

But try it, check your effluent from your DI, then experiment and test for Ca/Alk, post your results.

Good Luck

 

[crabbejoe]

It looks like Randy has already tested it inside and out. Way better than I ever could!
It's nice having people like him in our hobby. I'm constantly using his calculators.