spstimie

My background is all salt water and normal water flow is 20x-40x turnover. So a 40 gallon tank has 800 gallons per hour plus with about 10x turnover through the filter. I am moving my 1.5 gal plant tank into a 3gal. The 1.5 only had an air stone for water movement and no filter. I am cycling the 3 gal with a hang on filter, but it is rated for a 10-20 gal tank(can't find flow amounts for it). So how much water do I actually want to move? Before I purchase or build a new filter.

davemonkey

You dont' actually "need" to move water, it just helps circulate the water around the tank keeping detritus off leaves and ferts in contact with the plants. Believe it or not, some people use NO filtration at all. Some use filters for water movement only.

In a heavily planted tank, you might need to turn the tank over 8 times per hour, or even more. But in ligthly planted tanks, you might not need anything more than what you had. Don't spend the $$ on a filter until you see that you have dead spots (no movement or detritus accumulation) in your tank.

I have seen tiny HOB filters for the JBJ 3-gal pico-tope tanks. I'm not sure who makes them or where to get them though.

-Dave

Philosophos

Where is as important as how much. Powerheads, loc line, multiple filters and so on are all good methods for improving even flow throughout the tank.

-Philosophos

spstimie

I was actually worried about having too much flow. With the hob it created a lot of surface agitation and I made a diy co2 reactor so I didnt want the co2 just being churned out of the water. I ended up getting a Hagen filter from petco for $9. It looks much better than the hob. now it needs to finish cycling and I can move my livestock. thx for the help

Philosophos

HOB's are nasty for gassing off CO2. They suck up the CO2 rich water, which wants to diffuse the CO2 upwards and gas off at the surface. Then the filter lays the water out on top of the tank, even splashing the surface if the water line is too low.

I run my tanks at 10-15gph/gal. For instance, my 20g runs an XP1 with a rio 180. I do this because of high density plants. Sparsely planted tanks don't need this flow rate nearly so much. It's all about eliminating dead space and mulm/detritus deposits.

-Philosophos