Need BULKHEAD suggestions for used diy drilled 75

[Blorton]

Gang,

I just picked up a used 75 that has already been drilled on the bottom and that was obviously a diy job. There is one 1.5" drain hole in one corner and a 1.25" return hole on the back wall in about the middle of the tank.

Tha tank came with bulkheads that are both very loose in the holes and previously were sealed up with tons of silicone. These bulkheads adapt to 1" and .75" piping. Savko lists much larger openings for the same size piping. Does anyone know where I could find better bulkheads for these openings?

Yes, I could theoretically drill the openings larger, but I'd rather not do that. The return opening has a chip on the underside I don't want to make worse.

I'd appreciate any pointers.
Dan

[Geoff]

all i can say is take a look at some other sites. www.aquaticeco.com carries a bunch of different bulkheads. see if any of these fit your hole sizes. you need to click on get more info to see the hole sizes required for the bulkhead. www.marinedepot.com also lists hole sizes needed for their bulkheads.

G~

[Blorton]

Thanks Jeff. Your first link was one I hadn't yet found in Google. Real nice selection they have.

(And I even went looking overseas at metric parts. Nothing doing there either.)

After looking at the tank closer, I realised that whoever did this used a real bulkhead fitting on the return side, but cobbled together pvc junctions for the drain, which explains the abundance of clearance and silicone. I'm heading back over to the orange apron store now to see if I can find something better. Otherwise it looks like I'm buying an eBay diamond-coated hole saw. The blue apron and helpful hardware folks didn't have anything better.

Btw - do you happen to know the max flow for a 1" drain? I'll use the thin wall stuff to bump it up.


Thanks!
Dan

[Geoff]

a 1" drain will handle about 600gph.

G~

[Blorton]

Thanks, Jeff. Looks like I should be good for a pinch more than that.

After 5 hours in HD, I finally found that a 1.25" slip to 1" threaded reducer fits the drain opening very well. The big end, which will be the side in the tank, even has a bit of a funnel slope to it which will improve the flow rate. I'm abandoning the overflow box idea and will be using an inverted L shape instead. The top of the L will be slotted pvc. With roughly 18" of 1.25" head pressure, the choke down to 1" through the tank bottom should flow nicely. The exit from the choke is also 1.25" into a huge 1.25" ball valve, so hopefully I won't get too much cavitation and noise from that. I did a dry fit when I got home and it all looks real good and sturdy. Won't take nearly as much goop to seal up as the previous arrangement had.


The same fitting also just barely doesn't fit through the return opening. I'm thinking of just shaving the edges off the threads to make that work. (We're talking maybe a mm and it would clear.) If it does, I'll neck it down to 1" or .75" inside the tank so that the return pump won't have so much weight to work against. I'll just be doing a drilled t-shaped spraybar up top for that. Unfortunately, the bulkhead holes are too close to the rear wall to be able to use those handy disconnect fittings.

Had too much else to do today to get any of this installed, but am looking forward to getting it together this weekend and testing the drain rate. I'll be real happy if I can get 700gph out of it. If it does end up being 600 or less, I may drop back and order those drill bits. Really hoping to avoid having to run any powerheads in the tank. (even as nice as the Tunze are.)

Y'all have a great Christmas!

Cheers!
Dan