Tank and Pump Questions


Premium Member
Ok, some background here first:

A friend is building a 70G Reef. The tank's return will have three pipe exits from the main return pump (Blueline HD70). The ability for closed loops is an almost impossible task so all flow will have to be provided by the main return which will be connected to penductors. Also, we are keeping power out of the display so PH and Tunzis are not an option.

The output of a blueline HD70 is 1". Everything I've read says to achieve maximum efficiency from the Blueline; you should keep the pipe diameter the same as the pump's exit. This introduces an issue because the tank's return is 3/4".

Here are the questions:

1. My friend has an idea of trying to rasp out the return hole to accommodate a 1" bulkhead. The tank's bottom is tempered and I know you can't drill tempered glass, but could you rasp the hole without damaging the tank?

2. Even though the Blueline's output is 1", should he just reduce it to 3/4' and accept the loss of flow? The difference between 3/4" and 1" is almost 400GPH.

3. Will reducing the pump's output dramatically shorten the pump's life?

My thoughts were to reduce the pump to 3/4" and take the flow loss and the pressure increase. I believe the pressure increase will improve the efficiency of the penductors and give him an overall better flow. What do you all think?

Thanks :)
1. NOOOOOOOOOOOOOOO!!!! dont even think about that 3/4 is fine

2. lets come back to this. how many penductor do you intend to hook up? is their only one 3/4" hole going into the tank?

3. no
2. is the right answer (kind of). run 1" intle your bulkhead then reduce. use 3/4" thinwall pvc after the bulkhead. you can run at least 2 penductors with that set up and still get 5xs increase in flow. id say you end up with about 3500 to 4500 gph of flow.

you can actualy put a third one on and get about 6000 gph. use 2 45s instead of 90s were you can.

decreasing the the pipe size at the pump will Not incease the pressure at the nozzle it can increase the pressure at the pump. but not in this case your most of your pressure is going to come form the nozzle size .3" per nozzle.

penductors are great

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Thanks for the thoughts. The output of the pump is going to have 2 Tees at the top splitting off in three directions. Two of the outputs will have locline and penductors.

I agree, I love penductors too. I have one on my 75, driven by an hd55. It rocks.
He's also going to have a loop rock stand creating flow under the rock and raising the rock off of the sand. The loop will have less total output than an open pipe so really the return is going to have two major outlets.