Reef Mat 1200 install flow problem

[bob2307yahoo]

I just got a reef mat 1200 for my 320 gal display tank and I am using a seamless sump. Installation went well and really no big issues. I do have a problem with flow. The red sea website says you can run 2300 gph through it but I am having troubles at 800 gph. I don't think that with a gravity feed you can run much more through a 1" line. I have a COR15 and a COR 20 for returns and have had to turn them way down otherwise my overflow box fills and starts draining through the emergency overflow. Its a bean animal 3 outlet overflow.
Wondering if anyone has any thoughts. Here is a pic of the sump with the reef Mat.

As far as fleece use I am using 1 roll per 8 -10 days but the first one lasted 5 days. So I think as the water clears, and I can definitely see a difference, they will last longer.

Thanks for you help.

 

[Doctorgori]

I have 3 Reef mats and 2 COR pumps and can tell you no way can I run my pumps above 30% without a overflow happening.
I even discarded the convoluted tube and also switched from standard 1” pvc to the larger ID Eshopps red stuff and to no avail.
Heck I even hard plumbed directly. IMO I can’t figure out how to get the claimed flow

 

[bob2307yahoo]

I have a ticket in with them and will pass on what they say. Thanks for the comment

 

[Kodski]

What is that Y contraption that looks like its on the drain line right before it enters the reefmat?

 

[bob2307yahoo]

What is that Y contraption that looks like its on the drain line right before it enters the reefmat?

Its a WYE connector. I have 2 1 1/2". I use an animal bean overflow so have 3 returns. 2 are live and 1 is an emergency overflow. The Y connects the 2 active overflows.

 

[saulgoodmannnn]

Its a WYE connector. I have 2 1 1/2". I use an animal bean overflow so have 3 returns. 2 are live and 1 is an emergency overflow. The Y connects the 2 active overflows.

Any update with this issue?