Basic Tuning Approach

This is an Advanced Level product. Due to hundreds of different aquarium plumbing setups, pumps, sumps, ect, Synergy Reef DOES NOT Provide specific tuning assistance with this overflow. We can provide basic installation assistance, but setup and tuning to your aquarium is up to you. This can be done by anyone as long as you take the time to properly setup your system. Proper plumbing of the overflow to the sump also plays a big part in turning the overflow, not just the internal plumbing. If you are not capable of doing this, please hire a professional to do so.

The Shadow Overflow can be used on many difference sized aquariums with various flow rates. To be able to work with so many systems, each needs to be tuned to the specific flow of that system.
You will need to use a Gate Valve to properly tune the overflow. We DO NOT recommend using a ball valve. Ball valves are only used for On/Off functions and not for adjusting water flow. A gate valve will allow for the proper fine tuning of the overflow's flow to properly balance the drains.

The Key to tuning the overflow is balancing the flow between the primary and secondary drains. You do not want to use the gate valve to raise the water level in the rear box. If you need to close it more that 50%, then your pipe lengths are not correct. With low and ultra flow systems you may need to make your primary and secondary drains longer in lengths to raise the water level in the rear box.

We suggest starting with the basic pipe lengths listed in the Interior Box Tuning section. If you are still not able to get it to quiet down then do the following:
  1. 1.
    Figure out your flow rate that you are running. You may need to contact your pump manufacturer to determine your flow rate. It does not need to be exact, but within a few hundred GPH.
  2. 2.
    Once you determine your flow rate, the overflow flow has 3 settings, High Flow, Low Flow and Ultra Low Flow.
    • High Flow - Any system with over 1500 GPH running thru the overflow (shorter pipes needed)
    • Low Flow - Any system with 1000 to 1500 GPH running thru the overflow
    • Ultra Low Flow - Any system with under 1000 GPH running thru the overflow (longer pipes needed)
  3. 3.
    Once you determine your flow setting for the overflow (High or Low) you need to adjust your internal pipe lengths to fit your needs. The following is a good starting point for each.
    • High Flow - Emergency x 6.75”, Primary x 3” + U-pipe, Secondary x 4” with U-pipe
    • Low Flow - Emergency x 6.75”, Primary x 3” + U-pipe, Secondary x 5” No U-pipe
    • Ultra Low Flow - Emergency x 6.75”, Primary x 5.75” No U-pipe, Secondary x 6” No U-pipe
  4. 4.
    Turn on your system pump and leave the gate valve open 100%
  5. 5.
    Watch the flow of the drains and see what happens:
    1. 1.
      If everything is going down the primary drain and no other drains, then start closing the gate valve slowly, about 1/2 turn and wait about 1 minute. The continue to adjust the gate valve until it silences.
    2. 2.
      If you have water going down the primary and secondary, you need to adjust your Primary drain pipe length lower, or make the pipe shorter. You want most of the water to be flowing down the primary drain when the gate valve is 100% open.
      • You may need to adjust your secondary drain length as well once you lower the primary drain. Again this is something you need to look at and determine. The goal is to have 100% of the water draining down the primary drain with the gate valve open 100%. Only time this will not happen is in High Flow systems.
  6. 6.
    Check that your external drain pipes to your sump are sloped properly. Any up sloping can cause draining issues and create less flow to be able to run thru the drains. It also can cause noise in the rear box of the overflow. Try to not run excessively long plumbing runs to your sump. Keep it as short as possible, especially with High Flow systems.
Proper Drain Pipe Installation
Gate Valve Installed
Copy link