Planted Tank Enthusiast
Join Date: Apr 2011
Location: Pasadena, california
If you are converting a salt tank, then use as much of what you already have as possible and go for the sump. It provides a lot of options that aren't there in an otherwise filtered tank. You will need to have the bulk of your flow handled by a full siphon, with as small of a trickle as possible in your secondary drain line. You want to minimize splashing and turbluence in the sump, and seal any areas where this happens, namely where the water enters, and the last baffle the water has to pass over rather than under.
How you set up the sump can also cause you to lose some flexibility. On a drilled tank, there is minimal risk, but you are pretty committed to overflow color and location. I have been searching with no luck to find an example of an overflow box that looks like frosted glass but is opaque enough to not see the plumbing.
The way around this is to use an hob overflow, but you introduce some risk.
The tradeoff is basically, does the many benefits of the sump system and required overflow justify the loss in aesthetic options? I hate black and blue backgrounds, and being able to see the plumbing, but I love the functionality of a sump. Go figure...it's a personal choice. There have been many successful tanks run either way.