What size bulkhead to plumb a 10G?

[BlkGto]

For those of you that have plumbed your tank to a sump? What size bulkhead did you use? I think the common consensus is 3/4" and then use a ball valve to choke it down if necessary. Is this right or do most of you go w/ 1/2"?

 

I was thinking of plumbing a 10g to an extra 20G tank which will be used as a sump. I'm using a 20G instead of a 10G b/c the bak pak is taller than the 10G tank.

[SeaMountain]

Back when I used to rebuild motors for offroad 4x4's... The phrase was, "There's no replacement for displacement!" More cubic inches was where it was at. Same for your flow, bigger is better, and use a valve to adjust. You can always backoff, but it's tough to increase when you need it.

[wetworx101]

I would go with a 1" bulkhead...it's what I use on 10gallon nanos to get decent flow. 3/4" is too small for decent flow.

[ELGORDOINAVW]

at the very least go 1" although i would do 1 1/2-2" only because the bigger you go the less likely you'll get a blockage. also they are almost the same price, and seamountain is the man right you never know.

oh yeah wetworx 101 seems to always pass good info too. 3/4 is just too small.

[BlkGto]

Thanks for the info guys. I guess I'll go 1.5" to the sump and then use a 0.5" return pipe. Would this work?

 

And where do I go to get these plumbing supplies? I'd like to get one bulkhead and some pipes. Also three ball valves. One for the flow down, one for the flow up, and one for water changes.

 

Thanks!

[wetworx101]

I can be more specific. It does require some detail on your part however...the main question I have for you would be this:

Is the bulhhead being mounted at the surface of the tank...intended to skim water by itself...or a few inches below the surface as part of an overflow box???

This is why, and I hope you get a chance to read this before making any decisions...as it is very important.

The flow of water through a hole is determined by the holes SIZE as well as the DEPTH. As depth increases the flow through the hole will increase.

I did the calculations a while ago, and found these figures...

A 3/4" hole will have the following flows, with 0"depth being at the bottom of the hole. At 1/2" (thats 2/3rds of the hole) depth, 134.7gph. At 3/4"depth (no more surface skimming possible however because water surface is now at top of bulkhead opening) it is 164.9gph. This is not very adequate for a 10 gallon's overflow. If the hole is mounted deeper it will no longer extract from the surface. Blockages and the screen you use to block crap will further diminish these figures.

A 1" hole @ 1/2" depth will give 239gph. Much better, but just a little too close for comfort, and a little too restrictive (what if a snail sits in it? and the crap that accumulates...). At 3/4" depth, almost covering the hole yet still allowing surface skimming we are at 293.3 gph, and at 1" we are no longer skimming but up to 338.6gph. Now we are getting better.

A 1.5" bulkhead at just 1/2" is all the way up to 538gph. Very good. And at full immersion (1.5") we are all the way up to 933gph. Sounds good right? Even with a school of dead fish stuck on the strainer it should still have plenty of flow. But wait...lets see how we do this. A 1.5" bulkhead needs a hole over 2". This means that even if the bulkhead started at the top of the tank it would still leave a water line at about 2" below the top of the tank. Uh oh. And then for structural integrity, we must realize that bulkheads must not be mounted at the surface (aquarium trim would prohibit this anyways), but most people drilling like to leave an equal amount of glass around the hole equal to it's circumferance. That means our bulkhead could be mounted up to 2" from the surface, and this puts our waterline somewhere about 3" from the surface. Not to attractive.

This is why people use overflow boxes. Some like to silicone large corner pieces of acrylic with notched teeth into a corner of a tank, mounting the bulkhead on the bottom of the tank. I recently made an post in the DIY section on a cheap overflow box alternative using a bulkhead on the back wall and attaching it with PVC to a cut up brochure holder. Even this alternative keeps the surface of the water at the top, yet allows the bulkhead to be mounted a few inches lower. The flow is increased greatly, skimming on a large horizontal plane to the surface, decreasing the effect of clogging materials, yet what about the flow?

Well, at 1" depth, a 3/4" bulkhead can have 190.5gph going through it. A 1" hole at 1" depth will draw 338.6gph, not drawing from the surface by itself, but with a box it would...as well as having less likelyhood of clogging thanks to the box's larger intake area. If the hole is mounted 2" below the surface it will draw 478gph. Nice. Lets say we do go with a large baffle with teeth siliconed into the corner of the tank, with the bulkhead mounted at the bottom...that's 10+ inches of depth...over 1000gph possible! Even a 3/4" bulkhead mounted in this way with an overflow box could draw up to 426 gph...at just 5" depth! Plenty.

Moral of the story, bulkheads alone arent enough, I hope you plan on using a box. Sure, they have a purpose, as you can see at fish stores where they might use bulkheads on the tank w/o a box. I use 3/4" bulkheads on 10 gallons as the overflows, w/o the help of a box...they are freshwater fry holding tanks on a central system that only delivers 50gph to each tank...well within the capacities of a 3/4" overflow (I could go up to 150gph on each and be fine, 100gph with the sponges I mount on these )...but the flow is so low. A reef needs more. A reef needs a box.

[BlkGto]

Thanks for the great explanation. I'm actually thinking of using an overflow box located at the center of the back of the tank. Since it's a 10G long(width of a 20G), i was thinking of having two return pipes hooked up to a SCWD(always wanted to try one of these out:D). I figured this would ensure that there is no dead spots in the water.

 

I was going to place the overflow box at the left corner of the tank but opted against it if I was going to install the scwd. So w/ one return pipe, corner overflow. With two pipes, center overflow:)

 

Soo... given these facts, what size should I go?

 

I'm about to finalize things and I'm thinking 1" bulkhead going down to the sump and 2 0.5" pipes coming back to the tank. The tank is going to contain some stonies, zoos, polyps, and shrooms.

 

Oh... and two fish;)

 

Thanks again for all the help guys. This'll be the first tank i set up w/ a sump. I'm gonna change a 15G to a sump in the next month too!

[BlkGto]

Oh... I forgot to mention. The overflow box (which will be a 2x2 square) will run the height of the tank. I was planning on drilling the bulkhead at the back of the tank rather than the bottom. I'm creating this tank for a friend and I want to give her more freedom of tank placement.

[wetworx101]

I would put the hole as close to the bottom as possible. This would allow for a maximum flow of over 1000gph from a 1" bulkhead, as well as putting the bulkhead in a safer place (the center of the glass is where the pressure is exerted the most on the glass). I am concerned with the size of the overflow however. Why 2" by 2" by the height of the tank? It seems a little on the small side...but it would do I suppose for up to 300gph. I personally would go with a 4-6"wide and 1"deep box.

[BlkGto]

This is for an acrylic tank so i'm not too concerned bout the pressure on the tank.

 

I was thinking of using the following drain method:

http://reefcentral.com/forums/showthread.p...threadid=257906

 

With this method, I think i'd be good with a 2"x1"(or 2"x2") square placed in the middle of the tank. Because it's in the middle, the perimeter of the overflow box would be 4"(or 6") compared to 3"(or 4").

 

What do you think Snoochie?

[DSparks]

Great Thread, Mr. Wizard (worx) even got involved! I have a 10 gallon, and I just ordered all of the plumbing so that I can drill/install 1 bulkhead in the middle of the tank for an overflow, and 2 bulkheads for return (one on each side). I ordered everything in 3/4" size. After reading wetworx's response, I'm getting a little worried. However, according to wetworx:

 

Even a 3/4" bulkhead mounted in this way with an overflow box could draw up to 426 gph...at just 5" depth! Plenty.

 

So from what I understand, if I have an DIY an overflow that goes all the way down to the bottom of the tank, with the 3/4" bulkhead close to the bottom, I should be able to get enough flow into my fuge (under the tank) to keep up with a reasonable pump (ehiem) used to return the water?

 

Wow that was a mouthful. OK wetworx, it's time to do your stuff!

[wetworx101]

Yep. The calculations I did come up with that figure, now keep in mind that my calculations are based on a vertical hole which technically wont drain as much as a horizontally mounted hole (simple example: a 1" hole at 1/2" depth mounted verticaly would only be half underwater yet a 1" horizontal/flat hole under even 1/4" water would be completely covered). So if you were to put a hole on the bottom side of a tank, as long as it is vertical, it will have slightly less pressure on it than a bulkhead mounted on the bottom glass because of it's height. So a bottom hole will have a slight flow gain on a side hole, but I am not going to redo my calculations because were talking a minimal gain here, considering we would be at 12" or more of depth the flow on a horizontal bulkhead is already in the hundreds. More flow can be lost with screens over the bulkheads and accumulation of crud on a bulkhead's intake, easily over 20%. That's why I would never go with a bulkhead less than 1" unless we are using it for less than 100gph, or you are sure to prefilter the water enough to prevent clogging (D, I think you will be fine as long as you put a sponge or screen in your overflow above the bulkhead to keep any chunks away).

Just short of graphing the chart with line curves I have for flow by cross referencing hole diameter with hole depth, I can post the following:

1"bulkhead @ 1" depth=338.6gph

1"bulkhead @ 1.5" depth=414.8gph

1"bulkhead@ 2" depth=478gph

1"bulkhead@ 3" depth=586gph

1"bulkhead@ 4" depth=677gph

1"bulkhead@ 5" depth=757gph

...if you even need to know what the possible flow for a hole at a given depth is for more flow you dont have a nano anymore, and you are in the wrong forum.

3/4"bulkhead@ 1"depth=190.5gph

3/4"bulkhead@ 1.5"depth=233.3gph

3/4"bulkhead@ 2"depth=269gph

3/4"bulkhead@3"depth=329gph

3/4"bulkhead@4"depth=381gph

...you can draw the rest of the curve from there.

1.5"bulkhead, I dont think anyone needs these on a nano because 1" is enough for most tanks up to 40 gallons, and remember...a 1.5" bulkhead has more than double the intake area of a 1"...so were @ 933gph at just 1.5"deep.

[BlkGto]

This is turning out to be a great thread. I'll post pics of the tank when I'm done so hopefully it'll help others who are drilling their first tank. I'd like to thank all of that that have helped me out.

 

I'm gonna bring my tank to go get drilled at Tap Plastics today. I figure i'd drill:

- one 1 3/4" hole for the output. It will be drilled right in the middle, 2 1/2 " up from the bottom of the tank. This will leave approx. 1 3/4" from the bottom of the bulkhead to the stand the tank will be placed on. Then I'll buy some acrylic to create an overflow box 4" wide, 1" deep which spans the height of the tank.

 

- two 1 1/8" holes for water to come back from the sump. These holes will be located 1 1/2" off the top corners. This will leave approx 7/8" of room from the sides of the bulkhead to the sides of the back of the tank. I'm concerned if this is too close to the top or sides of the tank.

 

Any comments?

 

So then I went to marine depot to look at some plumbing supplies. That's when it got confusing. .. ???

 

http://www.marinedepot.com/a_ft_2.asp?CartId=#bh

 

1) I wasn't sure if I should get standard threaded, double threaded or double slip bulkheads.

 

2) Is the 1/2" ID Flexible Ball-Socket Joint Tubing used to position the direction your flare nozzles will point in the tank? If so, that seems like a good way to allow the user the flexibility to change where the currents are pointing in the tank once it's set up(just in case you have a coral that's retracting due to direct current or something).

 

3) Are the Y fittings what are used if you plan on placing more than one flare nozzle on your returning bulkhead? The answer is probably yes but I just wanted to make sure...

 

Wow.. it looks like plumbing supplied do add up.

[BlkGto]

Here's a pic

[wetworx101]

1) I go with double threaded always (no gluing PVC in, just twisting...easier to work with later as well). BTW, you might want to try reeffanatic.com, they had lower prices than anyone else when I bought my last $250 worth of bulkheads and lok-line...and by a wide margin.

2)Love lok-line. Love it love it love it.

3)you got it

BTW, looks great!

[BlkGto]

I'm bout to place my order for the plumbing when I noticed... how does the lok-line attach to the bulkhead? Does it fit snuggly inside? And is the attachment tool really necessary? I'm sure these questions are easily answered if I had the items in front of me but it's hard to tell on a computer monitor.

 

Thanks!

[wetworx101]

For lok line you can get a piece that has male thread on one side and a socket on the other...that is how you attach it (provided you have a threaded bulkhead...). The other end goes to nozzles (flat or round) or to a Y, as you mentioned before. The tool isnt really needed, but attaching them does require some brute force sometimes (then again I have a bad wrist so maybe I'm just a wuss).

[BlkGto]

Haha. Thanks for the response wetworx! I saw the parts you were talking bout. It's the socket x thread part. Now bout the tool.... all I do is type all day so I think i'll stick w/ the tool :

 

I'm ready to place my order now. Hey... what pump do you think I should go for? I'm thinking that there's probably gonna be bout 3' of head. Given that fact, Iam I better off with the MAG3 or MAG5? I was thinking of going 5 b/c I can always use the ball valve to taper it down...

[birdman204]

Duuuuuude, Awesome DIY info here.

[wetworx101]

Um, er, ah, lets see...you had a 10 gallon, right? And you were going to go with two outputs and a single overflow? I would go for a flow of about 300 gph (that's 150 per outlet) at most. That still is a little on the high side unless you plan on splitting the outputs again or something with the Y type lok-line so you have 4 outputs. A mag 5 might be a little much really, and I hate to see you have to restrict it so much if you get it. You would want to restrict it by almost 200gph...not good for pump. Just a side note: maybe spend the money on a nicer pump (not that mags are bad) like an eheim hobby pump (1252). They are the most reliable pumps ever made IMO, and better than mags because they are SILENT, now and 6 years from now. My personal fav on nanos.

[BlkGto]

Yep. Thanks for the reply. I'm getting so into this that I decided to add a sump to the 15G while I'm at it.

 

Yeah... I think I'm gonna set up the tanks w/o the Y. Don't see it helping much except to clutter things up. And since I'm planning on using the SCWD, only one outlet will be running at a time.

 

I only mentioned MAGs cause they seem very popular on the online forums. So I thought this is what people go with. I WILL need a quiet pump tho for the 10G because it will be located in a family room and I don't want people coming in wondering w what's vibrating in the room:angel:

 

What are some other quiet pumps?

[Dragon Reef]

Quick Question,

 

I have a 5.5 AGA tank that I want to put a 1 1/2" bulkhead fitting at the top left corner to make it a refuge. I will put a "Tee" inside the tank with the "Tee" laying horizontaly. Sorry, no pics . That way, you have a opening pointing down like the durso elbow, one pointing up for the air hole and one going into the bulkhead fitting. The output will flow into my main tank. Yes, the refuge is higher than the main tank. I do not wish to make bug soup . So, my question is, will the 1 3/4" hole in the top left of the tank crack over time? I was warned that it will not hold. Please Help. I do not want to spend the money to buy an acylic sump if I do not have to. Thanks.

[wetworx101]

Let me adress Dragon here for a moment...

I dont think it will crack, as the sealing ring that the bulkhead uses to seal against the tank also reinforces the glass around it by clamping all around it. The thing is that your overflow is no longer an overflow if you place the T on the inside of the tank...ie you will no longer skim the surface. You may want to reconsider your design. The other thing is how much flow do you plan on having? A 1.5" bulkhead is huge for a tank that size...so huge that it will leave your water level very low (I talked about this before in this thread). Lets see...1.5" bulkhead means over 2" hole, so another 2" from the top for adequate integrity around the drilled hole...that means your water level will be three inches from the top at least...alot to loose. If you go with an overflow box and then the right plumbing for noise elimination (many ways to do this) you can maintain a high water level. And you might as well reduce the bulkhead to a 1", that should be plenty. You can look for a thread I posted in called "small surface skimmer box?"...that should work...unless you are using baffles and didnt mention it. But unless you plan on running 500+ gph through this thing, a 1" should be fine.

[wetworx101]

Okay back to BlkGto...

Oh, a SCWD, I didnt take that into account. You can get away with much less flow with one of these because it almost doubles the output from each nozzle (a 300gph pump will deliver 150 to two nozzles if just split, but 300 through a SCWD is to each nozzle, even though pulsing, still 300gph). I am using a SCWD on a 20, and I had 500gph going through two outlets (250gph), but on a SCWD it it made blasts of almost 500gph!!! Whoah!!! I had to cut down to a 300gph pump. Now, a SCWD will impede the flow of most pumps by sometimes 20%. So with a SCWD, I would go for a pump that will deliver about 300gph. Thats 240 with the SCWD (-20%), and a little less for the height, maybe 10% or so (depends on height). So with a 300gph pump we will get pulses of about 200gph. So we want a good pump that does around 300gph, maybe a little more because it can be dialed down with a valve (but not too much).

I cant recomend a better pump than the eheim here (1252). I have a few mags, a couple large ones on a pond and a couple others running in the basement, because after about 6 months they all have developed a 'buzz' sound. I have already had to replace the impellers on the 1200 and 1800 once each in just two years. I also have a few eheim pumps (as well as the 2229, 2260, 2028, 2228, 2235, 2217, 2252 filters on other tanks). I cant say enough about them. They are silent. I used to have a 90 next to my bed with one...never heard it...right next to my ear at night. They have a very popular one that pumps 315gph. I have used 2 of the 1252 (315gph) for about 7 years now...never heard a peep, and never needed service. They are the mercedes of pumps IMO. I know of other good pumps, but they all have ratings of at least 700 gph...none small enough for a nano besides the eheim. The 1252 should run you about $60 online if you decide on one.

[Dragon Reef]

wetworx101,

 

Thanks very much for the reply. The hole is for a return from the refuge to the main tank. Since it is going back to the main tank, I do not really need the surface to be skimmed, do I? Also, since it is a refuge the flow will be low, should I get the 1" bulkhead fitting? BTW, the hole for the 1 1/2" fitting will be 1 3/4". Sorry to cut in on your thread BlkGto, I posted this question last week and did not get much feedback. Wetworx101, I look forward to your reply. You can also PM me, if you prefer. Thanks.