[Fluffles]

It depends what setup you have with your tank right now.

Most people running high tech tanks with CO2 will usually dose macros from one bottle and micros from another. I've seen some people use the third bottle for supplements like iron or excel.

If you're looking at making this as simple as possible, take a look at this thread. It uses a couple of components and timers to get the dosing pumps running. Read the whole thread before you decide to buy anything.

If you're feeling adventurous and want to learn some electrical and programming, take a look at this thread. It uses an Arduino microcontroller to accurately control when the pumps will turn on or off. It's more involved, but also provides a lot of flexibility to very accurately control the pumps and can even be expanded to do other tasks like controlling the tank's lights and CO2.

Any of the above options can be scaled down to have only 1 dosing pump.

 

[mistergreen]

you should dose nutrients too even at a low level.

 

[houbanna]

Here is a link https://www.google.com/url?sa=t&sou...sZXLKzSvw4gWDK2UA&sig2=K-MzZTAbE4FpI8j34KmKgQ

I built 2 works great!
Pull off the nozzle on the supplied canister and buy a cheap water spray bottle from the cosmetic/ ditty bag isle from wally world and and switch nozzles they fit perfect!

 

[talontsiawd]

If you are going to the trouble of doing it, I would just go ahead and do three unless it's cost prohibitive. One for Macros, one for Micros, one for Excel. However, if you just want to do one, there is no reason why you can't just do one. Most people who make this do it specifically for ferts so that's why there is usually a minimum of two pumps. Some people get really crazy with it and dose each fert though an individual dosing pump, most use 2 or 3.