Specific Questions for new 20 gal

[GayleMG]

Canister filters are pretty expensive, aren't they? I don't have a whole lot of money to get all of this stuff. Maybe someone on here has a used canister I can buy?
What about this one?
http://www.drsfostersmith.com/product/prod_display.cfm?pcatid=16742
or this
http://www.drsfostersmith.com/product/prod_display.cfm?pcatid=3597

 

[Slappy*McFish]

For a 20G tank a HOB filter or two should be fine. I've been running HOBs on my smaller planted tanks with CO2 for years without issue. Just be sure to raise the water level high enough so that the return water isn't splashing down into the tank waterfall style.

 

[BagelDog]

If you are going with a HOB filter I've had a good bit of experience with Marineland's Biowheel setup and AquaClear's filters. From what I've experienced, both are great filters as far as water parameters and bio stability are concerned. I've noticed the AquaClear has less of that waterfall effect, so I think it'd be the better choice for retaining CO2 in your tank. Again, great flow with relatively minimal water agitation.

 

[Paintballer99]

I just got a New MArineland C-160 for my 20gallon long, for $60 on ebay, you can find good deals there, but be careful for used ones and scammers! (and thats only about $10 more bucks from the HOT)