The height I am lifting the water is the same height as when I had all the extra equipment on it. I will look for a 400gph pump to replace the Eco, one of the tabs broke off so the impeller cover no longer stays on it. I was amazed how easily it broke off, and they never returned my email about replacement parts so I will never buy another Eco product again. Cheap parts with no customer service no thank you. This time I thought I would try an external pump to save room in my sumps overflow weir tower, it also keeps heat outside the tank (not a big deal in the north our summers never get hot enough for a chiller).
The ATO requires a reservoir, and I don't have much room under the bottom shelf for one. I suppose I could find a custom box, I could probably fit 5 gallons of water under that shelf because I know 2-3 2.5 gallon aquariums will fit under there. Now I think of it, the only place in the whole system that will drop is my overflow weir tower which has a very small volume of water! This will be the lowest point in my system, so that tower will need to be topped off daily. I never thought of this, now the ATO is absolutely necessary grr.
Edit: I thought about this more, the overflow tower does not have to be my only source of water that drops, I am thinking I could have extra tall weir fingers so that the level in the sump can rise and fall, however the higher the water rises on the weirs the faster the water flows so this may not work either...or at least I will loose my surface skimming function when the water is high? If the water rises too high it will allow the overflow tower to catch up with the sump level and then the surface skimming will not be as drastic.
I don't know if anyone has seen this video, but when I someday have the room I do plan on consolidating all my tanks into just two large long tanks...one simplistic open tank with lots of carpeting and the other would be jungly with a large variety of stem plants etc. The thing is if I went this far as to having two large tanks like this guy both at the same viewing height, I would link them with extremely large bulkheads and flexible hose. I would also light them on separate cycles so that the single body of water never has a nighttime photosynthesis shutdown period which causes the pH to swing. This is what they commonly do on reef tanks lighting the refugium at night, I am not sure however if this would require a closed loop pump between two large tanks. My thought was if you were using an external filtration system you could place the return on one tank and the export tube on the other tank, and as long as you use two extremely large bulkheads between the two tanks the flow should be equal between them without the need for a closed loop pump. Right?