I have a Tiger Oscar who's still quite small but he's getting a new home as we speak. I bought a 125 gallon salt water tank with a wet dry/ sump filter. I've cleaned it all out and washed it all down. Just to find out that the pump doesn't work. I will be installing all new plumbing so I am not to concerned with replacing the existing non-working pump with a match. I do however need to know how many GPH I need to have min. to run this tank crystal clear. Herbie is not my first Oscar, but this is the first tank I've owned that has a sump filter system. I know how messy these guys can be and I want to ensure he has the proper water quality.

The filter itself is a 20 gallon tank converted. There is room for a submersible pump inside the filter, but I would like to avoid that route since it has been drilled and already has the plumbing installed. The max height from pump to tank is 5'4". Thanks in advance if you took the time to read this.

a 20 gallon sump is a little small for a 125(should be about 35 gallons) but still will be adequate for the task. as for a pump you should look for something that will pump at least 500-600 gallon an hour at the head height you specified.

also sumps are by far the best bio filtration on the market however they do lack in the mechanical department. i would recommend a hob filter to help with the mechanical fitration part of the equation and for that i would recommend an aquaclear 110 for the job. jsut replace the bio media and carbon that they give you with another sponge and you should be fine.

i agree with necro......... hes the sump god !!!!!!!!

Thanks. I just wanted to make sure the LFS wasn't jerking me around.

Can I use a 1000 GPH pump? Does the size of the pump matter as long as it's a min. of 500 an hour?

usually pumps are rated at a zero head height. in other words that is the most water it can pump. as head height height increases the lower the gph rating. it is possible that you may need a 900 gph pump in order to get the 500-600 gph at your specified head height.
also one other thing to think about, is getting a variable pump so you can adjust the flow to more evenly match your overflow intake speed.

Hazeee wrote:

you can use any size more than that. for the lesser capacity,
it is better to have two so that you will have a fall back in
case of trouble or bugged down and during cleaning (one at a time)