A closed loop draws water from well below the surface of the tank. And feeds a pump that returns the water to the tank. It's closed so no air can get in. Hopefuly someone can do better than me.WW
My copperband eats frozen bloodworms. Its the only food I feed that he eats I feed it every day. I also bring up featherduster rocks from my sump. 8 months and still going strong. WW
Howman1 A nice pump that I use on my skimmer is the little giant 4mdqx-sc. 1" in and 1" out it has a fan and the noise isn't to bad. The mak4's are nice. And Iwaki pumps are widely used and liked I have a md30RLT. The Mag18-24 would work.
The Dolphin ampmaster3000 is very popular 1.5" in and...
What kind of water motion are you looking for. I use a mak4 on a closed loop just for water movement on my 240. And its not really that strong at 4'of head. Your 35gal sump will limit your choices as well. WW
I have a total system volume of about 400g with large basement sumps and am using just three 300w heaters. They are holding the tem at 78. The first year I had this setup I used a fireplug it melted. It may have been two small. Keep in mind you will lose head with a fireplug its like 4 90deg's ...
Tank looks good Nick. Wow all those fans that thing has to kick off some heat. If you want some rock with weed corals on it for the tank let me know. WW