The Puffer Forum

Can you use live argonite sand meant for marine tanks in brackish tanks,if you give it a good rinse to get rid of the bacteria before you add it to the tank?
Thanks

Yes I used live Aragonite in my brackish tanks. I didnt rinse it first and I should have, caused me some problems to start off with, got some very bizarre readings and a very scummy looking tanks for a few weeks. A good rinsing and you shouldnt have those problems.

Of course you can use it. But the question is why? Much below SG 1.018, the bacteria are likely to be stressed by being taken from a saltwater medium in the bag and then dumped into brackish water conditions in your tank. Many will die. Some might adapt, and provided the SG is above 1.010, I'd imagine this approach could shorten the cycling process. But in a low end tank, around 1.005, the bacteria would all die and all you'd be doing is adding a bunch of organic detritus for the filter to convert into nitrate. Even washing the sand (as you intend to do) won't achieve much, as a lot of bacteria will still be in place. So you may as well use a cheaper calcareous sand that will be clean and easier to use.

Cheers, Neale

If I had had more time I would've used something different, this was the only calcerous substrate I could find at short notice so it had to do. Readings were off for weeks. £40 to cover a 46"x12" bottom.

Unless you're using an undergravel filter (ideally reverse flow) the substrate will make a trivial difference to the hardness/pH of an aquarium.

Yes, if the water becomes acidic, some aragonite sand will dissolve and neutralise the acidity. But the overall effect will be small, because only the layer of water at the bottom of the tank is in contact with the very uppermost layer of sand. So the interface region, where the chemical activity is going on, will be small. You probably get better results putting crushed coral or pulverised oyster shell in the filter. With an undergravel filter, all the water is pumped through all the sand, so you get a much larger chemical interface.

It is identical in theory to why an undergravel filter produces good biological filtration, but a layer of gravel just sitting there without water pumped through it does not.

Bottom line, if all you're using sand for is decoration not filtration, you may as well use something prettier or less likely to cause the fish to "bleach" their colours (e.g., black sand or pea gravel). Concentrate on chemical filtration media (crushed coral) in the filter for buffering.

Cheers, Neale

So basically it was a complete waste of money. Good to know for the future. My Ph has raised up to around 8 from 7.5 in the tank but there is a lot of Ocean Rock in there so Would that be the reason for the rise rather than the substrate.