In article 3f606747$1@shknews01, David Willett wrote:

I
was thinking of using a Hagen 901 powerhead for the return from the sump.
It is rated at 900 gph. Is this too large?

It is too small. That powerhead is rated for 900gph at zero elevation
change. You are going to move water up several feet from the sump.

You are looking at a MAG pump
http://www.drsfostersmith.com/produc...=6&pCatId=4590

Or an external pump like Little Giant
http://www.drsfostersmith.com/produc...=6&pCatId=4614

click on more information to see the flow rates at a given height
(called "Head"). A single bend in your pipe adds to the effective
height that the pump has to work against. As does small diameter
pipe. As you can see from the graphs the flow rates drop off
considerably above 5 feet.

You need to research this more. The rec.aquaria.marine.* archives at
google.com is a great place to start. Don't be surprissed if you find
yourself useing 1 inch diameter PVC with a quality external pump.



So I need to have two sumps and
filters?

You only need one sump. But a sump can be several connected
containers. The water flows through the wet/dry, to the heater area,
to the return area. By carefull placement of baffles you keep the
return area free of bubbles and reduce any water fall noise.

You only want a single pump in the sump system. Use gravity to move
the rest of the water



I would like to keep a few Oscars in the tank so I know that I
will need a lot of filtration. Is there anything that I am totaly missing?

Use a section of the sump to grow hornswort or other weed. It will
improve the water quality greatly. Run the lights on the sump for
18hours.

Did you remember to brace the floor under the tank?

--
sg