Needs your input about plumbing idea

Hello!
I need your opinion about the following plumbing idea
I have a running bottom drilled with two corner overflows 135 gallon tank equipped with fluval 407 (hoses are running normal behind the back side) and fx6. FX6 is connected to both overflows from the bottom through a tee. The bulkhead sizes in each overflow are 1/2 for return and 3/4 for the drain. It is working fine but The would like to install another FX6 instead of 407. Any ideas how to get that connected? I was thinking about using both bulkhead for drains (1/2 and 3/4 combined should give me an adequate flow) and instal the original hose (1”) going behind the tank for the returns? Is this the best option I have?
I’ll explain why I want to use the bulkheads instead of sealing it and installing fx6s with original hoses French m behind. Two reasons. First, I’d like to not have dead zones inside the weirs and second, it want be easy for me to plug the bulkheads from inside. Outside plug should be enough but I would be sleeping better with both sides sealed shut.
Any ideas? How should I set both drains 1/2 and 3/4) inside the weirs, currently, I have a strainer on a 3/4 drains sitting almost flush with the bulkhead and 1/2 locline return in each overflow box. Should I set this up as 3/4 durso with 1/2 pipe with a strainer sitting 1” lower?
thanks

 

Just use one FX6 on each side of the tank connected to its own overflow.

The FX6 uses 1" hoses for both drain and return.

The bulkheads are great, so you can still use them.

You can just connect the 1" hoses from your filters through your existing bulkhead connections using a reducer. The water will just speed up through the reducer. But replace the pipes inside the weirs with 1". So you will have 1" pipe everywhere except going through bulkheads. You will get full flow from the filters with minimum plumbing complexity.

You are not really using the overflows, since you have a canister filter. So no need for Durso, etc. You just have a clean way to connect your canister through the bulkheads and it won't be visible in the tank Cool!

I have a tank like this too where I use a canister running through bulkheads. It's nice and clean.

 

Just use one FX6 on each side of the tank connected to its own overflow.

The FX6 uses 1" hoses for both drain and return.

The bulkheads are great, so you can still use them.

You can just connect the 1" hoses from your filters through your existing bulkhead connections using a reducer. The water will just speed up through the reducer. But replace the pipes inside the weirs with 1". So you will have 1" pipe everywhere except going through bulkheads. You will get full flow from the filters with minimum plumbing complexity.

You are not really using the overflows, since you have a canister filter. So no need for Durso, etc. You just have a clean way to connect your canister through the bulkheads and it won't be visible in the tank Cool!

I have a tank like this too where I use a canister running through bulkheads. It's nice and clean.

Thanks for the input! This was my original plan to get everything connected through the bulkheads but I found lots of threads on various forums saying that squeezing a return through a 1/2” bulkhead and channeling the drain through 3/4 instead of originally designed 1” hose can create a serious back pressure and eventually damage the motor. Do you think this is not true? I would not worry about a reduction from 1” to 3/4” for the drain but 1/2” on the return is scary

 

No, the short reduction in pipe size will increase the flow rate in the pipe through that section.

The higher velocity water has more friction but the friction loss is proportional to length. The bulkhead is very short so very little extra loss there.

Short lengths of reduced diameter have little effect. The water will be going in and out of your pump at the same pressure it was before. But with slightly lower pressure at the pump input due to the bulkhead. Thus slightly less volume.

Some of the pump’s energy is going in to heat the bulkhead instead of kinetic energy into the water. But the pressure is the same.

Plumbing system have places where the pipe necks down to a small hole, like in valves all over the place. These narrow sections just need to be short.

 

No, the short reduction in pipe size will increase the flow rate in the pipe through that section.

The higher velocity water has more friction but the friction loss is proportional to length. The bulkhead is very short so very little extra loss there.

Short lengths of reduced diameter have little effect. The water will be going in and out of your pump at the same pressure it was before. But with slightly lower pressure at the pump input due to the bulkhead. Thus slightly less volume.

Some of the pump’s energy is going in to heat the bulkhead instead of kinetic energy into the water. But the pressure is the same.

Plumbing system have places where the pipe necks down to a small hole, like in valves all over the place. These narrow sections just need to be short.

Awesome. Thank you!

 

Only thing to be concerned about with reducing the inlet house is clogging due to debris such as plant leaves other than that pump should easily compensate for the reduction

 

I use a prefilter foam on my inlet. Keeps big chunks out.