Excuse my ignorance - but what is a Powerhead and drip-plate

[Bubble_B0y]

I was wondering, what is a Powerhead.
I read many articles and they have mentioned it.
All I know is that it helps circulation and aeration.

Questions:

is a powerhead a filter on its own?
or
is a powerhead an attachment (does it need to be used in conjunction with another filter) ??


another question:

what is a spraybar and a drip-plate ?

do you buy it separately and attach it to a filter ??
or
do they come with a filter?

are they like airstones? do u need an airpump to operate it ??


sorry for the questions:
I use an aquaclear power filter/hang-on back filter.
They are simple and basic - nothing fancy.
They return water via a waterfall.

[fishyrican]

The powerhead is a small pump that sits inside your aquarium.

Here is a list of them:

http://www.bigalsonline.com/catalog/...2181;subcats=1

[Bubble_B0y]

Ok I just read that a powerhead attaches to an undergravel filter.
Question:
does this mean that the powerhead can power an undergravel filter - and hence you don't need an airpump to power the undergravel filter and you can buy a powerhead instead ??

Also, the powerhead has a function called REVERSE FLOW ??
what does this mean and what is so special about it ?

[fishyrican]

The powerhead would sit on top of the riser tube and pull the water through the gravel, under the UGF, up the riser, and back into the tank. The gravel acts at the biological filter. Reverse-flow reverses the direction.

In any event, I would do some research on AA regarding UGF. You will see many posts/members that recommend against them.

[Jchillin]

And hereis the spray bar. Instead of having your water come out of the single output nozzle, by attaching the bar, you can "spray" it over a larger area of the tank.