With the soft water in the Cape , I sometimes buffer my tank water with a bit of Calcium Carbonate BP. Going through my old aquarium stock, I found this old stash: (see pic below) Why is there an expiry date on this? Can it actually go "off" or is it still safe to use for the fish tank?
Hi, CaCO3 will not expire. Use it. I cant think of any reason why there would be an expiry date. Perhaps because it is a medical grade it requires one?
calcium carbonate is a mineral, it will stay the same for millions of years.. the white cliffs of dover are mostly calcium carbonate and they are around 70 million years old, so you should be fine with calcium form 2012..
That's what I thought, but since biology (and thus chemistry) was the first subject I ditched in standard 8, I just had to double check.
PS - Which is better for my purposes CaCO3 as above, or sodium bicarbonate (AKA baking soda)? I'm guessing I don't need the sodium in my fish tank...?
Apparently the reason for an expiry date on items that actually do not expire is because of the law, it has to be stamped on or it won't go on the market. Some thing I read about the FDA and whatnot... I will share an experience I had trying to raise my pH with bicarbonate of soda and epsom salt - the risk you run is putting too much in and raising it too high. I had to do several water changes to get the pH to 7.2 I would actually stick with CaCO3 - there are two different forms of this: lime stone grit and powder form. Personally, I do not like using the powder as it tends to cloud my water for a couple of hours. Perhaps adding the stone grit to your filter would keep it buffered - my dad is a chemical engineer and I asked him how long the stone grit would last, he said for years and years...
Depends what you want. sodium bicarb will increase the KH (buffering capacity) while CaCO3 will increase the GH (Hardness of the water).
Add some marble chips to the water. If the pH starts dropping the marble starts dissolving and buffers the water. Once the pH rises the marble stops being soluble and the rising pH stops.
Coral is different to marble but they are both made from carbonates. Coral will dissolve faster but I think it will still do the same job. Havent ever tried it to be honest. I went to a tombstone maker and asked them for off cuts of their marble. I got a few kg for free which I then gave out to people over the years. I currently have 2 or 3 small pieces left. Will probably last a year or 2 still.
marble is old coral that recrystallized during metamorphosis.. so they do the same thing, provide carbonates, but marble just reacts a whole lot slower..
