Thank you very much for taking the time to add your comments. I am very grateful that someone with you vast knowledge and experience has offered some of their insight here.

I am actually experimenting right now with a pair of red CFL spot lights, 23 watts each, one on each side. I know that is a little lower level than what I should have, but I want to see the effects of a red specturm of light. So far the growth rates have improved, however, I have also increased the stocking level and total amount of feeding in the tank as well. 4 weeks in and I still have nitrates and phosphates are undetectable by my salifert test kits and minimal (almost no) algae in the display tank. I will up-date this post once I have a few more weeks of use with the red CFL lights

I was the one who wrote the “Algae Scrubber Basics” summaries (Floyd R Turbo). Just a few comments, you sized your screen to be 2 sq in for each gallon, this is actually twice the size of the old volume-based guideline which was 1 sq in per gallon, but now screens are recommended to be sized according to the amount you feed. About a year and a half ago, the recommendation changed to 12 sq in (LxW) for each cube of food fed per day.

Also you’re a little off on the lighting, it’s 1W CFL per sq in split between both sides for “normal” level (LxW=90 sq in = 90W total, or 45 per side) or 2x that for “high” level light (which would be 90W per side) but then 1/2 of the photoperiod.

For the single sided screen, go right to the high wattage level because single sided screens are weaker due to shading happening quicker, meaning a 180 sq in screen would have 180W of light, all on one side.

For LEDs, it’s a different game, one 3W Deep Red (not 2700K Warm White) LED on each side of every 8 sq in of screen for normal level light, and one on each side of every 4 sq in for high level light (recent guideline recommendation). For low-power LED panels, there really is not much of a guideline because in general they are not considered to be very effective per unit area. So for your build, with a very much oversized screen that is underlit, it will work fine, but it will have limitations on capacity, meaning that 90 sq in / 12 = 7.5 cubes/day is not what the screen can handle, probably 1/4 of that at best – or about 2 cubes/day. Which is great, if that is what you feed, and if it works for your tank – keep it as is!!

We will be adding more species as often as we can.

Thanks for your help!

http://www.reefaquarium.com/2012/the-importance-of-water-flow-and-movement-2/

A 1.5 inch return line, even with the Y fitting ending in two line-lock should be able to handle around 2,500 gph of flow with no problems assuming you are talk about sch 40 PVC. That would be more flow than you would ever want in a 90 gallon display tank so there would be no need to change your return line. I would be more concerned about having a drain line (or lines) to handle your planned increase in flow.

I would suggest around 1300 to 1400 gph of flow in your main tank would be a good goal to aim for. Start by planning you sump (what you want in it, the size of the compartments….. and so on). Next plan your drain lines and return lines. You two main goals here would be to make sure your drain line will handle more than your planned flow, as well as identifying all the elements of your return line that will restrict your flow so you can choose the correctly sized return pump for your set up. You would likely want at least one 1.5 inch gravity based drain line (minimum)

I really do like external return pumps, but they can take up a lot of space if your sump is going under your display tank in your stand. Let me know if this answeres your questions

Also I notice on larger aquariums most are not using power heads/ fans in their tank; is this because they are running much more gph flow than is necessary to get proper flow through their return lines that they do not need to incorporate power heads/ fans? I find it to be a much cleaner more desirable look not having several power heads/fans cluttering the inside of the tank. I also only have 1- 3/4″ return line that ends in a Y with 2- 3″ flare loc-line nozzles; so I probably wouldn’t be able to get a tremendous amount of flow upgrading my return pump since I only have 1- 3/4″ return line.. I would probably need at least 1 more return line into my tank and they would probably both need to be at least 1″… just assuming here. If that were true that would of course be impractical since I would need to tear my system apart to make changes like that :/

Thanks for your help!