return pump flow?

AirIck · Jan 25, 2021

Hello, I am new to reefing and have questions regarding return pump flow. First, I have an AIO Fluval Flex 32.5. The specs of the return flow that came with the tank is 214gph. I have read on another threat that people have upgraded this to the sicce 1.5 which gives 387gph. Is there a benefit and/or adverse affect if I upgrade the return pump? I have heard conflicting reports from people saying that less is better in the sump/return area and then others saying more is better (10 -50x). I am confused what flow means within the return pump if I am currently running an mp10 for water circulation within the tank itself. So is return flow really needed with a powerhead running? And if so, is 214 to 387 a big enough difference to upgrade? Any and all information regarding flow and the benefits would be greatly appreciated so I can learn! Especially if I ever plan on upgrading to larger and larger tanks in the future. Thanks!

JosephM · Jan 25, 2021

Most people will run 3-5x flow through there system... sometimes up to 10x. I like to keep it around the 5x area. Do not get the flow between system and flow in DT mixed up. Depending on what corals you’re wanting 20-40x flow in DT is good. 214gph to 387 gph is a big difference just judging based on your tank size, I don’t know how large your sump is going to be. IMO you’ll be fine with the pump you have now unless you find yourself with not enough flow in your sump

Gtinnel · Jan 25, 2021

If you have your heater in the sump , which I think most people do, IMO you only need enough flow to the sump that it can keep the temp of your display at the desired level. Other than that the flow is mostly to make sure that your filtration (skimmer and fuge) are getting a constant replacement with display water so they aren't filtering the same water over and over. IIRC it seems like I remember reading that it's pointless to have the flow of your sump much higher than the flow rate of your skimmer.
When I first got into the hobby many years ago it was not uncommon to have a really high flow rate through the sump because it was often your main source of flow in the display, which is not the case anymore. The flow to my sump seems to be around 5x.

ca1ore · Jan 26, 2021

I don't think increasing flow from the stock pump to the Sicce will make any material difference. The sicce is likely a better quality pump, so noise levels and reliability are probably better reasons to upgrade. Frankly, I'd not bother.

AirIck · Jan 26, 2021

Thanks for the feedback, sounds like I can hold off on this. Would it be a good idea to purchase a backup sump? How often/likely do they malfunction and stop running? Also, how would I determine if the flow is good enough out of the return? Right now I can tell it seems to be pretty good because my PS1 protein skimmer I just installed is creating a ton of tiny bubbles that is coming out of my return causing my tank to look like crap. I'm currently in the process of reading through these message boards to see if this is normal or if I have an issue with my protein skimmer. All I know is my tank is brand new, and it was perfect for 3 weeks. I installed the protein skimmer and for the past 7 days it is nothing but millions of tiny bubbles all over my tank. I'm not sure if I should wait it out or unplug it. I was looking forward to purchasing my 2nd fish in 2 weeks but I'm worried to do that now with this current issue.

As far as my heater, that is a separate piece of equipment for my AIO but I do place it in the back container area where my sump and skimmer fit in the AIO tank.

Thanks for the feedback. This site is useful but it's a lot of information out there and I am so new to this I don't know what I don't know yet!