Torch Flow — Return Nozzle + MP40 Config Help (108G)

[LouieH94]

Hey everyone,

I’ve been dialing in the flow in my 108-gallon mixed reef and just discovered something I thought was worth sharing, and I could use your input to help optimize things further.

For weeks, I noticed that about half of my torch corals were swaying more aggressively than the others, almost to the point of looking stressed. Naturally, I assumed the issue was from my Ecotech MP40s, and I spent a lot of time adjusting power levels, modes, and positions trying to calm things down.

Turns out… it wasn’t the MP40s — it was the return nozzle.
It was angled in a way that created a concentrated stream directly across the left side of my tank, hitting the torches harder than I realized. Since correcting the nozzle angle, they’ve opened up much better.

I’m currently running:
- 2 MP40s on the side walls
- Neptune COR-20 as the return pump
- Mainly Euphyllia (torches) and LPS, with plans to add SPS in higher PAR zones

I used to have 2 more MP40s mounted lower portion of the tank to stir up the sand bed and prevent dead spots, but I removed them recently, and now I’m seeing algae building up on the sand bed where flow is lacking.

Looking for advice on:
1. What MP40 output (%) or mode works best in a 4ft tank with torches?
2. Do you recommend RFG nozzles or a different return nozzle setup with the COR-20?
3. Suggestions for solving low-flow areas on the sand bed without overwhelming the torches?

Any advice of your own flow setups would be hugely appreciated.
thanks in advance!

 

[Vivid Creative Aquatics Verified Sponsor]

the Random Flow Generator will definitely help in this case.

it will convert that straight, hard flow into a more natural variable and randomized flow. Your torches will still get plenty of stronger current, but not all at once and not all the time - but rather intermittently

I can make some recommendation on the right size RFG, based on the the type of return line you have, and the size and type of bulkhead. But in general, for that tank of that size with that return pump, I would suggest the follow options

Single 3/4in RFG flow kit, or the
https://vividcreativeaquatics.com/shop/3-4in-random-flow-generator-flow-kit-3-4-flex-series-rfg/
or Dual 1/2in Flow kit
https://vividcreativeaquatics.com/shop/ultimate-return-line-upgrade-kit-dual-1-2-flex-series-rfg/

1in RFG with some addition fittings.
https://vividcreativeaquatics.com/shop/flex-series-3-4in-random-flow-generator-rfg075-flx/
https://vividcreativeaquatics.com/shop/1in-modular-tube-5-knuckle-segment/

 

[Pntbll687]

Get some clean up crew in there to stir the sand up.

Get the coral onto the aquascape, then worry about the flow. From the video, flow looks ok for where the coral is now, but that can change when you put them up on the rocks