newbie with more dumb questions

I would like to put a scrubber on a friend's 40 gallon planted tank. He does have fish in the tank as well as plants. He does run CO2 12 hours and 10000K lights 12 hours. CO2 is on during the day, airstone on at night. He has been fighting algae that is horrid. So I have a few questions. Here is my background knowledge on aquariums. Used to run three 29 gallons with undergravel filters with powerheads. Actually have raised danios and flavus in the past. Currently running a 10 and 20 with HOB filters.

Was considering DIY protein scrubber but after reading the info on this site, I believe that a scrubber will do far more for water quality than a skimmer would.

So here are my questions:
1) Could I run a scrubber without an overflow box? I have never run an overflow box and see it is pretty much standard for a sump configuration. What is the purpose of an overflow box? Does it moderate the outflow current or what?

2) Would it be possible to tweek settings or mod the scrubber to run only 12 hours when the CO2 was not running in the tank? Has anyone out there with a planted tank using CO2 used a scrubber.

What a great site this is. Thanks to those who keep it up and running. Great info. Looking forward to others' experiences and thoughts on running scrubber on a 40 gallon plant/fish tank

1. Make an above-the-tank scrubber:

http://www.radio-media.com/fish/SumplessFeed.jpg




2. Lots of FW, but no planted that I know of. Yes you can OFF the scrubber light (not the flow) during the CO2 time. If there is nuisance algae, the scrubber will help. And keep in mind that the scrubber will add CO2 in the OFF time.

I have seen the info on how to build a gravity flow scrubber however my friend has said that he wants a sump style scrubber. It does make for a cleaner look. He has a fish room with several tanks and there is really not room to put scrubber in with gravity feed.

I would like to know why an overflow is used for a sump type installation. Does it help moderate the outflow current so it doesn't cause trouble with the fish? I have looked at several configs of overflow and have seen that sometimes there is some sort of prefilter in it. So if I need an overflow box, then the question is what would be best type to use. A weir overflow or a u-tube type? From what I have read the weir will have better flow.

I plan to use a ten gallon tank as we have several unused ones. I intend to tape aluminum foil to the outside to help maximize light reflection in the tank and on to the screen. I will be using only one side of the screen untilizing a small plant light that is unused. I will probably have two screens side by side for simplifying the cleaning process.

All suggestions are welcome.