Hi! I currently have a 150 gal display with another 30-35 gal in the sump/refugium. It is an island tank viewable from all four sides, so I am using a central overflow, specifically a Custom Aquarium Concealment Column (Link), that contains two 3/4” returns with 3/4” hoses running down to the sump. Due to the nature of this configuration, I am unable to increase the diameter of the returns. It is roughly a 5’ height increase from sump to return with a total of three 90 degree bends at the top of the hose through the return nozzle. I started out using a Maxspect Duo 9K - I was intrigued with the dual impellers for a single motor. It has worked adequately, but as the pump has aged close to a year, it is obvious that I am pushing the pump to the edge - it just does not do well with any head.
Since I have an Apex, it seems natural to switch to the COR pumps. I am leaning to replacing the Duo with two COR-15s, one for each 3/4” return. I prefer the COR15 to the COR 20 since I will not need the two power bricks, and can just plug straight into the Apex with the 1link ports. However, I have some questions:
Since I have an Apex, it seems natural to switch to the COR pumps. I am leaning to replacing the Duo with two COR-15s, one for each 3/4” return. I prefer the COR15 to the COR 20 since I will not need the two power bricks, and can just plug straight into the Apex with the 1link ports. However, I have some questions:
- Would two COR-15s be adequate? According to the flow diagram it would seem that I would get about 500 gph out of each with an estimate of 8’ of head (5’ of lift and an additional foot for each 90 degree). But what impact would a 3/4” return have on this flow compared to the recommended 1-1/4” return? I can run up to about 1200 gph total through the overflow, but would be happy with anything over 500 gph.
- This is very important - how can I coordinate the IQ level between the two return pumps to set the minimum and maximum flow rates? I don’t see anything in the existing literature to help with this.