overflow / plumbing sizing for 120gal 4x2x2

LXXero

New member
Hi all,

I'm getting my first big tank, I had 4ft of space to work with, and everyone always says go as big as you can, so I ended up with a 120 gal 4x2x2! My LFS is going to be drilling it for me to install an overflow and sump.

I'm planning on doing a beananimal setup with one of the modular marine overflows and I'm wondering what flow rates people would typically recommend for a tank this size? I'm also curious what size plumbing people usually go with for tanks around this size? .75", 1" or 1.5" ? I've been looking at the 1600GPH and 1800GPH overflow models, the main difference seems to be 1" vs 1.5" on the output bulkheads, I imagine the 1.5" might be nicer for the emergency drain although i'm not sure it'd matter as much for the full siphon lines. I've also read the wider tubing can help make things quieter?

I'd like to err on the size of "too big" than "too small" since it's not the kind of thing I ever want to have to re-do. I'm not even sure what i'm going to be putting in the tank yet, but I definitely want to consider future expansion and what not...this is my first time doing a sump / overflow type setup on a tank this big and it's going to be in a bedroom so I'm trying to keep it as quiet at the same time.
 
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I use 1" drains and a bean setup on my 120 with a Jebao DCT12000 pump at about 75% and it handles the flow just fine. I kind of wish I had gone up to 1.5" for the emergency drain since the water level rises fairly high over the E drain in the overflow. I have tested with the pump at 100% and did not have any issues, but in an ideal world I would like a little more margin for error. However, 1.5" piping would have made my sump more crowded.
 
On my 120, I use 1" bulkheads and 1 1/2" pipes; just like Bean's original design. My return pump is a Jebao DCS-9000 running at 50%. The plumbing will handle the pump running at 100% and is dead silent at any speed.

You can save yourself some money on the overflow box by buying 2 pieces of glass and doing a DIY C2C.
 
On my 120, I use 1" bulkheads and 1 1/2" pipes; just like Bean's original design. My return pump is a Jebao DCS-9000 running at 50%. The plumbing will handle the pump running at 100% and is dead silent at any speed.

You can save yourself some money on the overflow box by buying 2 pieces of glass and doing a DIY C2C.

Same, except substitute 150 gallon and a Blueline 70 or RD3-230 for the return pump. The RD3 flows less with my head height, but is about silent.
 
I should have mentioned, but I do not have any noise at all from my overflow even on high with the DCT-12000 and about 6' of head with the 1" drains. The only time I have noise is when my powerheads get the water really moving I will get some sloshing over the weir for the overflow.
 
So i've been going back and forth with modular marine, and they can do custom bulkhead sizing. I also finally spoke with my local fish store, my tank came in today and they're getting me the measurements to make sure the water level sits right when I have the custom box made.

C2C setup sure was tempting. My LFS was even showing me a C2C-like option that basically had a black acrylic box across the entire side of the tank, which is kinda cool but I didn't want tubing sticking out on the side, and I didn't want to consume the entire back of the tank. Ultimately the overflow box from MM is a nice compromise since I'll be able to do a lot more of the work myself and all my LFS has to do is drill me some holes....I've also been debating on whether to do something like a 3D background, and these super flush style overflows seem to leave a lot more free space in the tank which gives me more options to consider. that's also the main reason I didn't just get a pre-drilled RR tank, I hate the look of those giant black overflow towers on the aqueon RR tanks.

I was tempted by the 1800gph model, but that requires 2" bulkheads through the glass and then outputs to 3x1.5" bulkheads, but the 2" bulkheads to mount the box meant something like 3" holes drilled in the glass which seems overkill. I'd much rather keep it 1.5" bulkheads through the glass, which uses a 2 3/8" holesaw, I'd think 2x 1.5" bulkheads through the tank itself should be more than enough given what everyone's said here so far, so I think i'm going to avoid drilling for 2" bulkheads, it seems overkill and I feel the smaller holes will be stronger...

And for the overflow box itself, I was tempted to try something like 2x1" for siphon/trickle and a 1.5" for the emergency? But I could just go 1.5 all around and then reduce it too...It seems that I'm not too far off with the notion of 1.5 being better for the emergency...

I'm thinking the final decision is a 18" box with all 1.5" bulkheads. Then I'll reduce two of them down to 1" and leave the other one 1.5" all the way as the emergency....So basically the 1800gph model but with 1.5" bulkheads through the glass instead of 2", and all 1.5" bulkheads for outputs as well. I think it will be more than adequate, the 2" is probably overkill for nearly any situation you'd use that box in, you'd never want 3x1.5" drains running at once....at most you'd have 1 full siphon and some dribble down the other.

Not sure whether bean's recommendation of oversizing the input tubing matters if you go 1.5" for the bulkheads and just reduce to 1" afterwards? I read that once you're >=1.25 on the piping in the overflox box things tend to just work real nice and quiet? But I can't remember where i saw that stated....I do remember reading that >1" tubing seems to start siphoning better or something on the input end, I think that's why bean oversized it ? I can't recall exactly...
 
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I have the Synergy reef overflow on my 120 and it is dead silent with about ~1200gph going through it. I love the Internal/external design and it uses 1" drains with no problems. I did use spaflex and tried to limit the amount of fittings I used.
 
i looked at that one too, pretty similar setup, 2x1.5" bulkheads through the glass, but with the 1" outputs. I'm definitely liking the internal/external designs too. I'm figuring the 1.5" outputs is probably overkill, but I'm really only doing it for the emergency drain, which I'm gonna oversize a bit just for the heck of it, cause why not.

The sump I'm using is a aqueon proflex 4 which has 2x 1" inputs, so either way I've gotta get it down to 1" at some point. I'm not sure how much difference it makes going back/forth between 1" and 1.5" or what not? Does that provide any sort of effect I'm not aware of? Otherwise, I figure I'll probably just convert to 1.0" right off the bulkhead to the sump for the 2 siphon/trickle lines of the bean....then emergency will be 1.5" all the way to the return section of the sump, probably dumping in there from higher up so it's purposely loud.
 
Sounds good. Just make sure you use a gate valve on the siphon, tuning the drain is very "delicate" small changes can mean that in an hour your starting to draw air in your siphon or your secondary drain is starting a full siphon. Either way it is loud and you do notice it. The gate valve is just so much easier to adjust and well worth the $25. Also I drilled a small hole in the "trickle" line so I can visualize the flow. You can see the hole here in the pipe to the left. Sorry about the pink, my fuge light is on at the moment. Also seriously consider spaflex PVC. The elbows you see in the picture are the only fittings from the external weir to the sump. Even there I should have used 45's but it would have ment another trip to the big orange box store.
26782314191_c5da22d59c_m.jpg
 
Agreed. Between all three lines, only one needs a valve and a gate valve makes adjustment so much easier.
 
spaflex pvc, isn't that the stuff they use for pools? I've definitely seen it before.

i imagine it might be nice to put valves on all of them just for maintenance purposes? however I'll be sure to try and get a gate valve for the siphon line, i've heard this is way easier as well. although i've seen people using ball valves too, I imagine the tolerances are a lot harder to get right if you've got a picky setup.

That hole is kinda cool - does it just spill out in to the sump if any water gets through it? I've seen people use clear tubing before too, that'd also be kind of tempting! I'm not sure what kind of clear tubing you can use to mate up with PVC though.
 
If you get too much water going through the secondary drain it will "spit" into the sump. And yes spaflex is used on pools. I've seen it in 1", 1 1/4" and 1 1/2" sizes and it usually is sold by the foot from pool supply stores. It uses normal PVC cement and fittings. Also if Noise is an issue placing a oxo silicone dish drying mat under return pumps and using a short section of silicone tubing from return pump to the rigid plumbing of the return makes things dead silent. You can see what I mean on the right side of the sump from this pic when I was dryfitting everything
26655869805_5ce8c4b2dd_c.jpg
 
oh yeah that's not a bad idea, i've been using a small silicon baking sheet under my air pump on one of my other tanks, similar idea....that stuff you mentioned looks like itd be even better though.

i've probably even got some silicon tubing kinda like that, in various sizes, although probably nothing like 1"....i had it more because it could withstand high heat...it can get brittle though i've noticed, but i was using it under a lot more heat than a fishtank normally would generate.

i do like the idea of not keeping things completely rigid - first to prevent anything from putting excess pressure against the bulkheads/overflow box, and second to isolate the pump. of course submersible vs external pump is yet another debate I could have....i haven't gotten that far yet though.

I stopped by my LFS to see the tank today, and my sump had also come in as well which was pretty cool. My overflow box has been ordered from modular marine and it's being made for me as we speak. I'm hoping by the end of next week or so, I'll have the box in the hands of my LFS so they can template it out and get the tank drilled. I'm gettin pretty excited, but i'm trying to be patient as it'll probably still be weeks before I'm remotely ready to start it all up.
 
Reefer PT,

Looking at your photo, have a few questions out of curiosity:

1. Why did you put a gate valve at the return side?

2. There are two white clamps (looks like a hook) on the drain side pipes. Do they work well? They don't really help carry the weight of the pipes, just help keep the pipes in position, right?

3. What are the two clear canisters for near the drain pipes?

Thanks!
Julius

If you get too much water going through the secondary drain it will "spit" into the sump. And yes spaflex is used on pools. I've seen it in 1", 1 1/4" and 1 1/2" sizes and it usually is sold by the foot from pool supply stores. It uses normal PVC cement and fittings. Also if Noise is an issue placing a oxo silicone dish drying mat under return pumps and using a short section of silicone tubing from return pump to the rigid plumbing of the return makes things dead silent. You can see what I mean on the right side of the sump from this pic when I was dryfitting everything
26655869805_5ce8c4b2dd_c.jpg
 
LXXero,

I can’t believe my case is so similar to yours – came from same planted tropical fish tank for last 10 years in a 4’x2’x2’ 120G tank.

I am probably a week ahead prepping the tank to reef ready. I spent quite some time researching different over flow options, and will go bean animal setup as well. Ended up with the low profile overflow box from Modular Marine as well. Here are the requirements I told them. Got the shipment last week – beautifully made!

I reduced only one of the 3 bulkheads from 1.5” down to 1”. This reduction gives me vertical distance between the siphon pipe and the middle pipe (not the dry emergency which is the tallest). I didn’t have the limitation you had from the sump (I don’t have a sump yet), but I imagine your two 1” pipes will give you even more vertical drop so your system will be even more stable.

By the way, I drilled the 2 holes in the back of my tank this weekend (1.5” ABS bulkhead). I chose to drill from inside the tank toward outside, because the surface inside the tank is the sealing surface and the exit surface will always have more glass chips than the entrance side. I plan to paint the back of the tank this weekend.

1. http://modularmarine.com/collection...box-bulkhead-mounted-aquarium-surface-skimmer
2. Black cover for the external box
3. Drilling template included.
4. Modifications:
a. The 2 pass through bulkheads (mounting the overflow to the tank): reduce both from 2" bulkheads to 1.5" bulkheads.
b. Out of the 3 drain bulkheads, keep 2 of them at the original 1.5" size, but reduce the 3rd bulkhead down to 1" bulkhead. The middle and left drain are the two larger (1.5") bulkheads, and the one on the right side is the 1" bulkhead.
c. The outlet of the 3 drain bulkheads should be threaded. All others (i.e. inlet of drain bulkheads, and both sides of the pass through bulkheads) should be slip.
d. The middle drain will be a dry emergency drain pipe and thus the tallest among all 3 drains. Pls ensure the braces on the top of the external boxes will not be directly above this middle drain.
e. I will let you decide the horizontal spacing among the 3 drain bulkheads as well as the two pass through bulkheads. Be sensitive to the clearance needed by pass through bulkheads (despite I can rotate the standpipes, and/or cut the "tail" of the pass through bulkheads, I prefer clean design).
 
If you get too much water going through the secondary drain it will "spit" into the sump. And yes spaflex is used on pools. I've seen it in 1", 1 1/4" and 1 1/2" sizes and it usually is sold by the foot from pool supply stores. It uses normal PVC cement and fittings. Also if Noise is an issue placing a oxo silicone dish drying mat under return pumps and using a short section of silicone tubing from return pump to the rigid plumbing of the return makes things dead silent. You can see what I mean on the right side of the sump from this pic when I was dryfitting everything
26655869805_5ce8c4b2dd_c.jpg
Sorry to hijack the thread, but is that a drop in filter sock area? meaning its stand alone from the rest of the sump and could be pulled out if you wanted? I was thinking of doing that too, have you found any drawbacks?
 
Reefer PT,

Looking at your photo, have a few questions out of curiosity:

1. Why did you put a gate valve at the return side?

2. There are two white clamps (looks like a hook) on the drain side pipes. Do they work well? They don't really help carry the weight of the pipes, just help keep the pipes in position, right?

3. What are the two clear canisters for near the drain pipes?

Thanks!
Julius
1. I put a gate valve on the fluval SP6 because it is a bit over the GPH rating I wanted for the tank so I have the ability to throttle back a bit if needed.
2. Yes, available at HD and lowes they work great, easy to snap pipe out if needed too.
3. They clear canisters are 2 separate BRS reactors plumbed off a dedicated manifold (not the return) I have them running the output from GFO and ROX carbon to the filter socks as I had a bit of HLLE problems with my tangs that I'm hoping catching the carbon dust will help with.

My stand is very tall in comparison to the standard stands so I am taking advantage of the vertical space as much as possible by going up with the reactors.
 
Sorry to hijack the thread, but is that a drop in filter sock area? meaning its stand alone from the rest of the sump and could be pulled out if you wanted? I was thinking of doing that too, have you found any drawbacks?

That Is exactly what I have done. Now the tank has been running for only 3 weeks now, but to date I have not seen any drawbacks. The acrylic construction was very easy and filter changing is a breeze, don't even have to shut anything off. I am surprised how fast the socks clog compared to my previous 1 sock set up but this tank is bare bottom, lots of flow from the MP40 and dual RW15s and 1200gph turnover. I have yet to find even one pile of detritus forming so it is all going to the socks. If I did it again I may have gone with the 7" socks instead of the 4, but the refugium right next to the sock filter is tumbling the cheato so nice, any smaller and it may not have.
 
3. They clear canisters are 2 separate BRS reactors plumbed off a dedicated manifold (not the return) I have them running the output from GFO and ROX carbon to the filter socks as I had a bit of HLLE problems with my tangs that I'm hoping catching the carbon dust will help with.

Wow, I have no idea what you are talking about but it does sound very, very interesting!

Regarding the plastic hooks, do they provide support to the weight of the pipes/connectors above, or simply keep them in the right vertical position?
 
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