jilly

It makes me nervous because I havea 4 year old who is in to everything, and the idea of a CO2 tank in the same house as her gives me scary thoughts..

Is there a simpler, or child safe way to use CO2?

What are the limits of what you can do without adding CO2 to the water?

Squawkbert

Rules of thumb:

CO2 isn't generally *needed* unless you're using a lot of light (>2WPG)
For smaller tanks, Flourish Excel is a reasonable, economical substitute for any CO2 system.
For smaller to medium sized tanks (up to ~30g - though I'm getting away w/ it on a 46g), DIY CO2 is a reasonable substitute for pressurized.

While DIY CO2 is less hazardous than a CO2 bottle, I wouldn't be too inclined to worry about a CO2 bottle as long as it was clamped in place somehow. I think much more significant hazards are found in dangling cords and lighting fixtures. Obviously, all ferts, test kits & food products have to be put somewhere safe too.

For lots of info on what people do w/o CO2, check the NPT forum (El Natural).

Sandman333

Squawkbert has the right idea,
DIY CO2 can definitely be used, depending on the size of your fish tank.
However, even pressurized CO2 can be pretty safe if it is locked into a cabinet or in your aquarium stand. I haven't heard anything about CO2 disasters of this type.
To keep it child-safe I wouldn't leave anything exposed, just the little hose going from the needle valve or bubble counter into the fish tank. It can be made even safer if you are using a Canister Filter and have an inline reactor.

There are many plants that can do well without CO2, I have grown Water Sprite, Ludwigia, Java Ferns, Pellia, Giant Hygro, Bacopa, and Christmas moss without it. In fact, I still haven't used any CO2, my setup should be complete within the month.

I know all this information may seem intimidating, I didn't know anything 6 months ago. Read forums around for a while and you will definitely learn more than you ever thought could be learned about planted tanks.