Powerhead

[sr20det]

I noticed a lot of powerheads on he bb on peeps tanks.

Whats the purpose on top of spray bars say from a external filter?

Is it just a case of better co2 distribution, or water flow?

 

[foxfish]

Within the secrete of successful plant growth & zero algae lies Co2 in every square inch of aquarium space!

 

[bigmatt]

Flow is king! The aim of the game with planted tanks is to ensure nutrients (ic. co2) are delivered to every leaf of every plant in order tomaximise growth (and rapidly remove the waste products excreted by the plants). This typically gets quoted as the 10x rule (ie stated flow should be at least 10x the volume of the tank per hour). Sometimes this can be achieved using just filters, but sometimes due to tank size/shape/hardscape/planting powerheads are used to ensure flow is optimised. The best and most easily interpreted method to check adequate flow is that all plants should appear to be "waving in the breeze" - if not it's algae ahoy!
Hope this helps,
Matt