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View Full Version : Balancing full syphon with return up.


shamoo
03/06/2018, 02:40 PM
Hello all

My tank has been up and running for a couple of months now and all is good. put my first 6 fish in, 4 Chromis and 2 x Cardinals, all doing very well and eating well and water is very good, any way to the problem in hand...

Due to the noise factor of the overflow i have decided go the full syphon route, i have 2x1.5" overflows from DT to sump which is controlled by the overflow valves. An issue i'm facing is the sump where my return pump is housed, the water runs too shallow. the retun pump is eheim compact+ 5000 and is returning just under half maximum flow rate. i was aiming at 5x the tank volume so around 3000 lph, i dont want to turn the flow down anymore, if anything i want to increase it but i cannot seem to get the right balance of more return flow, without running the return pump section dry in the sump. if i open the control valves open more to alow more flow into the sump the syphon noise returns.

i have read, watched many videos, tried silencer method but i think the issue lies with my sump set up. i'm even thinking about calling a local "expert" to assist. since the tank is doing well i don't want to keep messing with it other than water changes and start enjoying it more. i do plan on upgrading my return pump to Vectra M1, i find this Eheim difficult to increase/decrease the flow.

Has anyone had any similar issue's? can anyone suggest anything wrong with the sump?

mcgyvr
03/06/2018, 03:06 PM
A display tank can only drain the water from it slower than or as fast as its being pumped into it.. It can never drain it faster (assuming you have a proper overflow box)..
It seems like you are saying that your return pump is pumping water into the overflow faster than it can drain it..
If so you need to open your valves up as they are creating a restriction so that the system cannot drain as fast as its being filled up..

Or slow your pump by putting a valve on the output side of the pump (thats the proper way to reduce the flowrate of a pump)..

We really need to see whats going on with your overflow and not your sump to give a more specific answer but the concepts I stated above always hold true..
The sump is likely not the problem..

Salty Waffles
03/06/2018, 07:54 PM
You're trying to run both 1.5" drains as a full siphon? Are these the only drains?

If this is the case, it sounds like you need to rethink your plumbing again. One 1.5" full siphon should handle the flow you're looking for. The full siphon drain needs a gate valve to achieve fine tuning adjustability. Not a ball valve.

The other 1.5" drain should be setup as an open channel or Durso style standpipe with no valve. This is your "Emergency" drain. Remember, no valve in this drain.

This is a Herbie setup. Set your return pump where you want it. Then adjust the gate valve in the full siphon drain until you have a slight trickle through the Emergency drain.

The Emergency drain should be set 2 or 3 inches higher than the full siphon in the overflow. This part is important to avoid siphon noise.

If I misunderstood the question and your setup, then disregard everything I said.:lmao::worried:

oldhead
03/07/2018, 08:29 AM
1) you don't need that sponge filter.
2) you really don't want more flow through the sump than what your skimmer is rated at. Flow for the tank comes from the power
heads or a CL.
3) what they said.

shamoo
03/07/2018, 03:42 PM
Thanks everyone, appriciate the feedback

you have pretty much confirmed what i was thinking,
1. change ball valves to gate valves
2. extend 1 overflow to make it an emergency overflow

At the moment both overlow pipes are the same level in the DT, mistake on my behalf. both are 1.5"

thanks again