Tank conversion
 

I'm always thinking to convert my current tank to keep guppy, but this tank is sum tank with overflow for me to keep Pleco before (4ft length but 2.x ft for width and height, tats y I think quite ok to keep guppy).. so is there possible for me to convert it to keep guppy? I don't think overflow tank and such strong pump is suitable... or I just need to seal everything off? Any better suggestion? Thanks

You can use SS mesh for the overflow combs instead. I use it to keep out small fish like tetra. But the fry will likely go through.

If you want to save the fry then add a durso pipe or a raised pipe to the overflow to raise the water level. Also leave the first chamber of the sump empty. Then you can fish out the fry.

Or you can just shut down the sump and go with some other kind of filter.