SP6 if you can fit it in your return chamber. Its a big pump. The sp4 probably wont quite give you as much flow as youd like. For 135w the SP6 is near unbeatable in low head pressure, high flow applications. FWIW I just adapt the SP6 to 1.5" PVC near the pump outlet then plumb with that up to a "T" and then use reducer bushings to get down to the desired return inlet pipe diameter. That will give you the least restriction possible. Not that youll need it with this pump. You'll have to throttle it back Im sure, which actually saves more wattage. Youre likely only going to pulling 100-110W or so at the end up the day, and running one of the most reknowed motor blocks for reliability, the askoll brand. Best of luck with the tank!
I don't disagree Why I said use a good AC pump there is no reason to use a DC controlled pump for a return, just more risk of problems. My mag 18 is dead silent and reliable plus it is 12 years old.. My tank is 280 gallon total system 300 gallon so I would need more flow than a single Syncra 5. The Sicce have good reviews, I never used one but would not have a problem buying one when the need comes up. I will not use another jebao for return pump even though plenty of people do. I could get away with a wave pump or skimmer pump stopping or fail but never want the return pump to stop. If you are out of town like say 10 hour drive or by plane not much you can do if the return pump fails.
A vote for the Sicce, I have the 9.0 and really like it. I just cleaned it after it’s first 6 months of use, and was very happy to find that it is extremely easy to clean, and didn’t have much gunk and no calcification. The Vectras are a huge pain in the rear to clean, and I had multiple issues with them.
I have a 6 year old reef octopus hy5000 that I ran on my 125. Never cleaned it once. Until I took my tank down recently. Super quite and I think the reliability speaks for its self. Now It is going to be used on a water mixing station. Probably going to be going with the hy7000 on my 140 when I get it.
