Plumbing / Pump question

[DW66]

So, I was trying to lessen the number of pumps in my sump and the factory manifold that came with my tank didn't push enough water so replumbed today. (Attached photo).

Varios 8 moving 750 gph through a 1” pipe using a barb at the pump, 3 inches of silicone tubing, and another barb to connect to the hard plumbing.

Goes to a T, the top of the T is a reducing bushing converting the pipe to the 32mm that the tank came with and continues up into the display.

The left one goes to a 3/4 reducer bushing and then to the manifold assembly.

2 3/4” Spears ball valves, attached at the top with a tee and then terminating on the right with a 90 drop to the second valve.

The first valve terminates at the bottom with a 90 bend into a 1/2 inch threaded barb and is currently feeding my algae reactor at a measley 172 gph with the ball valve wide open.

The second one is terminated at the bottom again with a 90 degree bend 3/4 to 1/2 . This time into a 1/2 adapter to a push to connect John Guest fitting which is feeding my carbon/gfo reactor. It is only pushing 67 gph through the reactor via 1/2 od tubing.

Why am I getting such low flow from the manifold? I had hoped to run a biopellet reactor from it but that needs about 280, which is where I’d prefer my algae reactor to be.

I don’t have room for three separate pumps
In the sump, if I use a varios 6 or similar to feed just the manifold, if I can figure out how to attach and plumb it would under the same low flow rates?

Thanks.

 

[Subsea]

I am a little slow today. Would you draw up a schematic to illustrate what you said.?

 

[Pistondog]

While it looks neater, hard plumbing takes a toll in flow with 90s and Ts.
These add up to flow restrictions.
Flexible tubing and larger radius bends would help, where feasable.
Optimizing your bends by using 2 45s vs 1 90 would also help.
Also check other devices, valves and manifolds for restrictions.
Some are designed with larger orifices.

 

[FindinNemo]

It sounds like you’ve put a lot of effort into optimizing your sump setup, but running into flow issues can be frustrating. Let’s break down your situation and explore some potential solutions for increasing the flow from your manifold.

Potential Causes for Low Flow:​

1. Head Pressure: The flow rate (gph) of your pump can be significantly affected by head pressure. If the pump is pushing against a lot of vertical height or through numerous bends, this could reduce the flow rate substantially. Check the height difference from the pump to the highest point in your system and refer to the pump’s performance curve to see how much flow you might be losing.
2. Pipe Size and Restrictions: Reducing the diameter of your plumbing (for example, your transitions from 1” to ¾” and then down to ½”) can create bottlenecks. Smaller diameter pipes can restrict flow, and since you mentioned using barbs as connectors, these can also create flow restrictions. If possible, keep the plumbing as consistent in diameter as you can to maintain flow.
3. Bends and Fittings: Each bend and fitting increases resistance in the system, lowering overall flow. It might be beneficial to minimize sharp turns and use sweep elbows instead of standard 90-degree bends where feasible.
4. Ball Valves: While you may have them wide open, ball valves can still create friction loss, especially if they are not specifically designed for low resistance. When possible, consider using a valve with a larger diameter or a type that allows for smoother flow characteristics.

Possible Solutions:​

1. Upgrade to a Higher Capacity Pump: If you decide to upgrade to a Varios 6 or a similar pump, you might gain additional flow, but keep in mind that the flow may still be limited by your plumbing setup. Understanding the limitations that exist in your current plumbing setup will be crucial.
2. Reassess Your Manifold: You might consider redesigning the manifold if space permits. A larger diameter manifold with fewer fittings and minimal bends can significantly improve performance. Optimize the layout to minimize vertical lifts and sharp turns.
3. Increase Pipe Size: If your setup allows, considering increasing pipe sizes throughout the manifold (e.g., keeping everything at 1” or going to a larger size throughout) can help reduce restrictions and improve flow.
4. Direct Pump to Each Reactor: If you’re looking to run several reactors, you might need to use separate pumps for each one unless you can pull enough flow through your manifold. Limitations in flow might necessitate reevaluating your setup to make the most of available resources, even if it means being creative with space.

Testing Your Current Setup:​

• Measure Flow: You can use a flow meter to accurately measure the output from each section of your manifold. This can help identify where the most significant losses are occurring.
• Experiment with Adjustments: Try adjusting configurations, such as lowering the vertical rise from the pump to the discharge point or temporarily removing some fittings to see how that impacts flow. Each change can provide insights into where the restrictions are.

Conclusion:​

Given your constraints on space and the desire to minimize the number of pumps in your setup, carefully assessing your current plumbing and considering alternative configurations may be key to achieving the desired flow rates. With thoughtful tweaks and adjustments, you should be able to find a balance that supports all the reactors you want to run. Don't hesitate to share any updates or further questions you have as you work on this—good luck!

 

[Snoopy 67]

You are putting a lot of back pressure on that pump by decreasing the pipe size.
There are only a few DC pumps that handle back pressure and Varios is NOT one of them.
I would switch to an AC pump along with the other recommended solutions.