Syncra 3.0 vs 5.0 for return 125g dual corner overflows

[Chris Romani]

I recently purchased a standard 125g dual corner overflow bottom drilled tank. My plan is to run a single pump for the return and split it to each corner of the tank. I have a 40 g long converted into a sump with a protein skimmer section and also refugium section. My question is... with the purchase of the tank the previous owner also gave me his Syncra 3.0 return pump that was used in his setup (714 GPH). I was in a local fish store and was told this pump is not adequate for what I am trying to do and I would need minimum a Syncra 5.0 (1321 GPH). Is this true or was he trying to make a sale? I understand more flow the better but will rely also on power heads in the tank to move water. Also I was concerned with this added flow through the sump- will it be an issue to the refugium which is also in the sump? Thanks for any info!

 

[Meat locker]

Figure out what turnover rate you want and what's the actual total volume after displacement from rock, sand, and equipment. I think you want at least 4x per hour. I have a sicce 3.0 on a redsea reefer 170 about 40g total volume after displacement. I ended up with prob around 15x. That's a lot more than I need, but I can throttle it back. I also have the extra flow if I ever need to add a manifold to power other stuff in the future. Also, dont forget to take the height of the return into consideration. Its 714gph at 0 feet. At 5 feet it's at 505gph. Overall, I'd say the 3.0 might be at the bare minimum for that size system.

 

[Chris Romani]

Figure out what turnover rate you want and what's the actual total volume after displacement from rock, sand, and equipment. I think you want at least 4x per hour. I have a sicce 3.0 on a redsea reefer 170 about 40g total volume after displacement. I ended up with prob around 15x. That's a lot more than I need, but I can throttle it back. I also have the extra flow if I ever need to add a manifold to power other stuff in the future. Also, dont forget to take the height of the return into consideration. Its 714gph at 0 feet. At 5 feet it's at 505gph. Overall, I'd say the 3.0 might be at the bare minimum for that size system.

Thanks for the information

 

[A sea K]

Im running the 3.0 on my 80gal with the same sump. Just right if not just a tad underpowered, go with the 5.0 especially if using two returns as there will be additional headloss in the added plumbing.

 

[A sea K]

I understand more flow the better but will rely also on power heads in the tank to move water. Also I was concerned with this added flow through the sump- will it be an issue to the refugium which is also in the sump? Thanks for any info!

This is a valid concern and needs to be considered as too much flow through the sump/fuge is not ideal. I still think the 5 is the better fit, you can always divert any additional flow to run reactors and such or simple install a valve in the return line to regulate the flow if needed, but I really think you should be pretty close if running dual returns.