This is impossible to answer or address without knowing what you are trying to achieve.
No reason what you are doing is bad per se, you might burn out your LED strip with spray from your skimmer though. I can think of much cheaper sump lighting - Amazon LED systems with dimmers come to mind, like 22 bucks for all the components. And the LEDs are replaceable if they get sprayed.
They'll be fine with the dimness of ambient light. But you yourself might very well appreciate having a small light to make working in your stand more pleasant. I did that on my last build and will certainly be doing so again.