Naturaly buffering top-off water

[Instinct]

I had this plan some time ago, but never did it.

Basically, I want to build a tank (around 8 gallon capacity) to perform auto-top off with fresh water.

Since this water is just sitting there, what would happen if the tank had a thin layer of say, crushed oyster shells, sand, or maybe just crushed coral? Now add a very small powerhead for circulation, with maybe a venturi for to keep the water well oxygenated.

Given the low PH of RO/DI water, wouldn't this start to dissolve the material, bring the PH up, and add a bit of calcium? Would it be enough to be worthwhile?

My only concern would be any weird growth that may try to grow. (bacteria etc) As long as it wasn't major, the top-off tank could easily be cleaned and the buffering material replaced on a monthly basis or something.

Just trying to get some feedback before I wasted time on it. Or I could run a little experiment with a bucket and check the water parameters after a few days. What do you guys think?

 

[Anonymous]

The Ro/DI will definitely dissolve more carbonate than freshwater, but its pH is decieving, and won't be much help unless it is naturally carbonated (high dissolved CO2, but that will kill off the resin quickly). Anyway, in a nut shell, it won't be very useful, but certain won't hurt anything either, just a lot of work to keep it clean.

 

[Instinct]

wow quick response, thanks.

Bummer though, thought it might help with CA.. I hate dosing and CO2 is out of the question...

On to other projects then

 

[kgross]

Your plan will buffer the water slightly, but very slightly. You can figure out how much calcium you are adding to you make up water. Just build the setup (even a temporary one), and measure the Ca in the water going into the tank. Then you can decide if it adds enough calcium to do any good. Personally I don't think it will add enough to do much of anything.

Kim