300g Plumbing....Need Ideas

[PeacockKeeper]

Hi All,

I've been away from aquariums for over six years now and am finally getting back into it with my sons. I bought a 300 gallon acrylic tank and it has been in storage all these years. I never got the chance to set it up when I bought it from the previous owner, who also never set it up. I've spent last week reading through all the forums on here to get an idea on plumbing but would like to get your inputs/ideas on how you all would approach it.

Through reading on here I will be planning on using Durso pipes for both the overflows and drain it into a 55g sump. The overflow holes drilled at the bottom of the tank are 2-inch diameters and planned on using 1.5-inch bulkheads with 1.5-inch PVC for the Durso. Is this correct?

Would anyone know what the purpose of the holes on top of the tank are for (holes 1-4 in the image)? The two holes back of the tank, can be the return lines but if I wanted to move the tank as close to the wall as possible, can I use the holes on top of the tank for return lines? On each corner behind the overflows are openings that I can run PVC pipes thru.

How would you all go about plumbing this tank?

Thanks in advance!!!

 

[DN328]

That makes sense. I can see holes #1 and #4 used for returns. I am honestly stumped with #2 and #3 and the purpose of those on top.

 

[BIG-G]

They may be there for passing wires through for running internal equipment like power heads or airlines for areation and sponge filtering

 

[pacu mom]

Is there only one hole in the bottom of the overflow boxes? If there are two holes, the return line can be plumbed up through the overflow box, out, and then back down through a hole in the top of the tank. By doing it this way, all the pipes are hidden under the canopy or the overflow box.

This hole is for a return line

The other holes can be used for uptake/return lines for redundant filtration.

In the front is a return line exiting the overflow box and entering the tank from the top. Notice all the other holes we made in the top of our 300 gallon tank for other filtration besides the wetdry filter.

I had the tank builder put eleven holes on the top of my big tank for my mechanical filtration. I would rather go through the top of the tank, than from the back, sides or bottom of the tank. Three of the eleven holes

 

[PeacockKeeper]

Thanks for the responses...

I am probably going to cap of the two 2.5-inch holes in the back of the tank, run 1-inch piping from the pump up through the openings behind the overflows, and plumb into the 1.25-inch holes (Holes #1 & #4) on top of the tank for the return lines. Holes #2 & #3 will be unused and just covered with a piece of plexiglass. Thanks again!