lilmiss

tank as long as i treat it first, i live in a hard water area that produces loads of lime scale and my nitrate levels are asways really high even after a water change

Semantic Drift

I'd think it would be fine - the only problem I can see is that it would probably lack a lot of the dissolved minerals that fish and plants need to regulate diffusion, as well as for use as nutrients (for plants, at least). I'd recommend adding a healthy dose of aquarium salt, just to make sure the ion concentrations stay even. Helps with gill function and all that.

COBettaCouple

what fish do you have in your tank?

griffin

if you're using bottled water, you probably don't need to treat it. but, certain types of bottled water don't have the minerals that your regular water will. you might want to supplement those back in.

what kind of fish/plants do you have in your tank?

Luniyn

Are you only using the bottled water or are you mixing some bottled water with your water (50/50 or 60/40, whatever)? If you are only using bottled water, then you are starting with a blank slate pretty much (similar to using RO water). Some of the bottled waters have a little bit of minerals left over in them, but usually not enough to create any kind of good buffer in your tank. The purpose of a buffer is so quick swings in your things like pH don't have a chance to occur which would basically kill all of your fish. So you would probably be better off using a combination of tap and bottled water (plus it will be cheaper then having to buy enough for the entire tank you could cut that down by at least half). You should get a water hardness test (one that has KH and GH for both amount of buffer and water hardness) and then you will have to experiment with the combination of tap to bottled water. Depending on the type of fish you want you can find the best mix accommodate them.

lilmiss

at the moment i have 3 mollies,2 zebra danio,3 golden barbs, 4 black widow tetras, a fewneons, 1 pleco,a red tail shark, 2 frogs, a few shrimps, a strange looking bottomfeeder, 2 albino cat fish and 2 goldfish( they are due to go in own tank on wed, i have no live plants at moment as goldies rip them out,

COBettaCouple

Using salt would be harmful with the catfish.

Sarcastic

I used to do this.

There is a product from API called Electro-Right, use that. Will adjust both GH and kH. I find that it spoils after a while, so get a smaller bottle and replace it often rather than getting a larger bottle. Also, you will need to use a pH buffer to keep your pH up.

Also, use only either reverse osmosis or steam distilled water. Do not use "purified" or "drinking water" as that usually has some cholarmine in it.

Eventually, I decided to buy a $75 R/O distillation unit and save myself the grief of carrying all those bottles of water around. It also saves money over time.