New tank - drilling for a closed loop - need some plumbing advice

[WhatCouldGoWrong71]

1) You can’t talk me out of a closed loop.

Now that that is behind us -

Tank is 48”x48”x18”, it will be come an acro/sps bare bottom. Lots of halides. I need lots of flow.

- Bulkheads will be Haywards (2” , 1.5” and 1”)
- AC Hammerhead pump 6000 GPH (2”/1.5”)
- 16 3/4 RFGs
- 4 - 1” bulk heads near the corners of the tank (8-10” in from both directions) each of these will have up to two RFGs each
- 2 - 1.5” bulkheads each with a 4 way (spa version) so each of these will sport 4 - 3/4 RFGs

Above is option one, that would have all the plumbing below the tank. Option two is just one 1.5” bulkhead in the tank. Then have a manifold inside the tank that feeds a network of pipe that can be placed where needed. Being a bare bottom look down, as the tank grows in, you won’t see the pipe much. Over time the coralline will just cover everything. However, I will need to make sure that it floats slightly above the surface (1/4”) so that detritus can move freely throughout the tank.

Thoughts? I need to drill this in the tomorrow. It gets wet Monday/Tuesday. Rock/sand from TampaBay Saltwater gets here Monday PM (doing a dual sump with one sump simply being a deep sand bed)

 

[WhatCouldGoWrong71]

When plumbing the RFGs, where each RFG is, doesn’t each leg have to be equal lengths? Or, am I safe as the entire thing will be pressurized? Sorry, not the world’s greatest plumber. The first closed loop I ever did is my big tank. It functions really really well what I did in the big tank. But the in tank piece is not equalized really, or at least I don’t think it is.

 

[UncommonSense]

For starters; are we positive that the bottom pane is not tempered?

If not, I vote for a single large bulkhead for the return; manifolded inside the tank!

As we all know; bulkheads are known to leak… less is better in that regard!

Also, less holes in the glass pane = stronger pane!

When plumbing the RFGs, where each RFG is, doesn’t each leg have to be equal lengths? Or, am I safe as the entire thing will be pressurized?

The RFGs are the primary plumbing restriction; if all of them are the same size, they will all flow more or less equally, regardless of pipe length!

 

[WhatCouldGoWrong71]

Yeah, it’s a Glasscages tank. I talked with Joe. I do like these Hayward bulkheads. I wish more people were familiar with them, when I build my big tank I spoke to an engineer familiar with this subject and these are rated for saltwater with far far worse abuse then they will ever see in our tanks. Agree with you on less holes is always better. I’ve got way more holes in my display in my living room sitting on my hardwood floors.

I can’t believe 10 years ago the only real option are those horrible $10 bulkheads they still pedal today. Those are good for overflow boxes, not loops. When I built my big tank, I was dumb and had them spec the hole size for the Haywards, talk about overkill. $300 in bulkheads sitting in 5 inches of water, shaking my head.

So, @UncommonSense the. It doesn’t matter if I decide to pop all the holes in the glass and just plumb the underneath so that it is the simplest and easiest way to plumb? No need to balance all the lengths? Anyone else?