Bulkhead/overflow what do I need to know? - The Planted Tank Forum
Reply
 
LinkBack Thread Tools Display Modes
post #1 of 21 (permalink) Old 08-08-2011, 07:34 PM Thread Starter
Planted Tank Obsessed
 
Taari's Avatar
 
PTrader: (7/100%)
Join Date: Jul 2010
Location: Washington
Posts: 352
Bulkhead/overflow what do I need to know?

I want to build another 5.5 gallon custom tank like the one I built for my mom. The difference will be that I want mine filtered and heated with a 5.5g (standard) sump/refugium.

My idea was to have the bottom glass drilled in a back corner and install a bulkhead with a 1/2" diameter clear acrylic tube going all the way up to about 1/2" from the top of the tank. The underside would be attached to a tube that drains into the refugium. There would then be a pump in the sump side of the sump/refugium that would pump the water back up into the tank through an acrylic Lily pipe that I will attempt to make myself.

So basically the water in the tank would only fill to the top of the acrylic pipe, then drain down the pipe into the sump, get filter, and then sent back up to the tank.

I want to do this rather than an overflow box as I feel its more attractive, easier to hide, and easier to install (I hope).

My questions then are:

1.) How far from the corner of the bottom glass should I drill the hole so that the glass remains structurally sound?

2.) What kind of plumbing fittings do I need to attach a 1/2" OD acrylic pipe into a bulkhead?

3.) What diameter will the hole have to be to accommodate the 1/2" pipe and the fittings?

Thanks for the input!
Taari is offline  
Sponsored Links
Advertisement
 
post #2 of 21 (permalink) Old 08-08-2011, 07:47 PM
Planted Tank Enthusiast
 
wespastor's Avatar
 
PTrader: (1/67%)
Join Date: Dec 2009
Location: End Game
Posts: 537
Quote:
Originally Posted by Taari View Post

My questions then are:

1.) How far from the corner of the bottom glass should I drill the hole so that the glass remains structurally sound?

2.) What kind of plumbing fittings do I need to attach a 1/2" OD acrylic pipe into a bulkhead?

3.) What diameter will the hole have to be to accommodate the 1/2" pipe and the fittings?

Thanks for the input!
Answer to 1. This distance is equal or greater than the diameter of the hole determined in number three (3) below. For example should you need a 2" hole the edge of the hole would need to be 2" from the side of the tank; and for a e placed in a corner that means both the back and the end.

Answer to 2. Start with a standard bulkhead fitting if you can find one that small. You may be able to use a heavy duty PVC cement to get the job done. Most PVC is white but you can use Krylon sry paint flat black to cover that. Be careful when gluing an Bob's your Uncle.

Answer to 3. Once you have found your fitting in #2 above the diameter of the hole required maybe self explanitory.

Hope this helps.

Best wishes,
Wes

I quit!
wespastor is offline  
post #3 of 21 (permalink) Old 08-08-2011, 07:53 PM Thread Starter
Planted Tank Obsessed
 
Taari's Avatar
 
PTrader: (7/100%)
Join Date: Jul 2010
Location: Washington
Posts: 352
So long as none of the fittings are higher than 1" from the bottom of the tank, they will be covered by the substrate, and I'm going to have plants in front of the tube anyway.

Also I thought of another question. Will 1/2" diameter tube allow enough water out to keep up with the water being pumped in through another 1/2" diameter tube? I'd rather not have to get two sizes of acrylic, but it's fairly cheap, and it would probably cost the same to ship both together as just one alone, so it's not a huge issue. Maybe I will go to the hardware store and see what I can find for bulkhead fittings and decide on my tube size based on that.
Taari is offline  
 
post #4 of 21 (permalink) Old 08-08-2011, 08:33 PM
Planted Tank Enthusiast
 
wespastor's Avatar
 
PTrader: (1/67%)
Join Date: Dec 2009
Location: End Game
Posts: 537
Quote:
Originally Posted by Taari View Post
So long as none of the fittings are higher than 1" from the bottom of the tank, they will be covered by the substrate, and I'm going to have plants in front of the tube anyway.

Also I thought of another question. Will 1/2" diameter tube allow enough water out to keep up with the water being pumped in through another 1/2" diameter tube? I'd rather not have to get two sizes of acrylic, but it's fairly cheap, and it would probably cost the same to ship both together as just one alone, so it's not a huge issue. Maybe I will go to the hardware store and see what I can find for bulkhead fittings and decide on my tube size based on that.
Are you real good in physics? There is a solution to the question; I just cannot get my head around the math right now. Look to: http://www.phy.cmich.edu/people/andy...s/chapter9.htm

But that's the long answer. I'm sure there is someone that can answer that more directly and difinatively.

Best wishes,
Wes

I quit!
wespastor is offline  
post #5 of 21 (permalink) Old 08-08-2011, 10:09 PM Thread Starter
Planted Tank Obsessed
 
Taari's Avatar
 
PTrader: (7/100%)
Join Date: Jul 2010
Location: Washington
Posts: 352
That's way more math than I am capable of, lol.

I just went to home depot and looked at their bulkhead fittings, they DO have a 1/2" one, and a 3/4" one. They are threaded on the inside though. I'm going to be putting a non-threaded tube into it. How do I deal with that? I was thinking I could just put a good layer of silicone on the threads and put the tube in and put another ring of silicone around the top?
Taari is offline  
post #6 of 21 (permalink) Old 08-08-2011, 10:27 PM
Planted Tank Enthusiast
 
wespastor's Avatar
 
PTrader: (1/67%)
Join Date: Dec 2009
Location: End Game
Posts: 537
Quote:
Originally Posted by Taari View Post
That's way more math than I am capable of, lol.

I just went to home depot and looked at their bulkhead fittings, they DO have a 1/2" one, and a 3/4" one. They are threaded on the inside though. I'm going to be putting a non-threaded tube into it. How do I deal with that? I was thinking I could just put a good layer of silicone on the threads and put the tube in and put another ring of silicone around the top?
Me too lol
Way to much math ... I a firm believer in calculaters ... which button is the flow button?

Next time you go to home depot see if they have a fitting that goes from that threaded part which is most likely a pipe thread (tappered) to a slip fitting (straight) that can be glued. I would not trust the silicon over the long term and have it leak.

BTW It's good your planning this out a little in advance ... some rush right in and ... "Help I have a leak now what?" or worse, "My tank overflowed why?

Best wishes,
Wes

I quit!
wespastor is offline  
post #7 of 21 (permalink) Old 08-08-2011, 11:09 PM Thread Starter
Planted Tank Obsessed
 
Taari's Avatar
 
PTrader: (7/100%)
Join Date: Jul 2010
Location: Washington
Posts: 352
Thanks alot for all your replies. I always like to plan stuff out ahead of time. This project is going to be very slow, as I have limited funds, so I'll be getting a piece here and a piece there and doing as much myself as possible.

I went to Lowes and looked for a bulkhead and they did not have any, but I did notice they had the type of fitting you are talking about to go from threads to a slip, so I can do that. I also found Bulkheads online here http://www.diamondbitsusa.com/index....d=13&Itemid=57
as well as the diamond coated hole drill needed. They recommend a 1 1/2" hole drill for a 3/4" pipe though! That seems really big O.o Is the bulkhead really 3/8" thick on the walls?
Taari is offline  
post #8 of 21 (permalink) Old 08-08-2011, 11:13 PM
Planted Tank Enthusiast
 
Booger's Avatar
 
PTrader: (27/100%)
Join Date: May 2004
Location: Seattle, WA
Posts: 576
Have you ever heard an open standpipe? How much do you enjoy the sound of a perpetually running toilet? Also, I wouldn't run a bulkhead smaller than 1" on any tank for fear of flooding.

A Mame style overflow (I've seen DIY versions) or even standard overflow box would be my choice. You can even build one out of clear material, a la ADA.



Booger is offline  
post #9 of 21 (permalink) Old 08-08-2011, 11:29 PM Thread Starter
Planted Tank Obsessed
 
Taari's Avatar
 
PTrader: (7/100%)
Join Date: Jul 2010
Location: Washington
Posts: 352
The tank I am putting this on is 30" long, by 8" tall, by 6" deep. An overflow box would be incredibly huge and bulky, even made of clear material. I don't mind the sound of running water, and I almost always have a fan or the TV going anyway, since I can't sleep without white noise, even in the winter.

My plan is to have nothing in the tank for equipment but a clear acrylic lily pipe or spray bar as an outflow, and a glass CO2 bell diffuser.

The website I linked above said a 1/2" bulkhead will work for a pump 150gph or less, and a 3/4" bulkhead will work for 360 gph or less. I'll probably be using a 200gph or less pump. Likely 160, actually, since I already have one on another tank and it lifts the water a foot or so with plenty of force to spare.
Taari is offline  
post #10 of 21 (permalink) Old 08-08-2011, 11:32 PM
Planted Tank Obsessed
 
PTrader: (1/100%)
Join Date: Feb 2011
Location: Jackson TN, U.S.A.
Posts: 470
Before anything else: make sure the bottom of the tank you're looking to drill is not tempered glass! If it is, it'll just break on you when you try to drill it.

Quote:
Originally Posted by Taari View Post
Will 1/2" diameter tube allow enough water out to keep up with the water being pumped in through another 1/2" diameter tube?
The question you really want answered is will a gravity-powered drain .5" in diameter be able to move as much water as your PUMP pushes back into the tank through whatever size input pipe.

There are a couple of ways to approach that, the simplest would be to buy an adjustable flow pump or put a valve on the return line and simply turn the inflow down to a flow the drain can handle. However, that might not be the best way to go.

For a more complex answer, I recommend you have a look at this site.

The other thing you're likely to run into is that a drain like you're describing is susceptible to being quite noisy -- think of how a bathtub drain sounds. That webpage has some information along those lines as well, but its suggestions aren't going to be directly adaptable to what you're describing. The simplest answer to that one is going to be a larger diameter drain tube. How large will depend on how much flow you want to drain through it. This might be an acceptable option. You could prowly manage it with clear tubing, if you're clever/creative/persistent enough.

What you're describing can be done, but it's likely to take some fiddlin' with. Since you are planning ahead, some experiments with plastic buckets, or the like, might be a desirable idea. I'd hate for you to get into dealing with the glass one and then try to adjust that after the fact.
NatCh is offline  
post #11 of 21 (permalink) Old 08-08-2011, 11:36 PM
Planted Tank Obsessed
 
PTrader: (1/100%)
Join Date: Feb 2011
Location: Jackson TN, U.S.A.
Posts: 470
I should add that I like this idea. I like it a lot. If I'm understanding you correctly, you'll end up with something that looks an awful lot like the visible parts of an undergravel filter, which are quite visually unobtrusive. The idea alone is worthy of a "whiz-bang neato!"
NatCh is offline  
post #12 of 21 (permalink) Old 08-08-2011, 11:38 PM Thread Starter
Planted Tank Obsessed
 
Taari's Avatar
 
PTrader: (7/100%)
Join Date: Jul 2010
Location: Washington
Posts: 352
The tank is one I'm building myself, so I'm positive the glass is not tempered. Thanks, I will check out the sites you listed.

And that is exactly what I am going for, the clear tube that goes up to the top for an under ground filter, only without a power head on top.
Taari is offline  
post #13 of 21 (permalink) Old 08-08-2011, 11:52 PM
Planted Tank Enthusiast
 
Booger's Avatar
 
PTrader: (27/100%)
Join Date: May 2004
Location: Seattle, WA
Posts: 576
Quote:
Originally Posted by Taari View Post
The website I linked above said a 1/2" bulkhead will work for a pump 150gph or less, and a 3/4" bulkhead will work for 360 gph or less. I'll probably be using a 200gph or less pump. Likely 160, actually, since I already have one on another tank and it lifts the water a foot or so with plenty of force to spare.

If the sound doesn't bug you, I am envious.

The reason I suggested a larger bulkhead is the ease of which a snail, dead fish, or plant matter can clog an open 1/2" or 3/4" pipe. If that happens, there's water on the floor and in your eyes.
Booger is offline  
post #14 of 21 (permalink) Old 08-08-2011, 11:59 PM Thread Starter
Planted Tank Obsessed
 
Taari's Avatar
 
PTrader: (7/100%)
Join Date: Jul 2010
Location: Washington
Posts: 352
What I am thinking I may do is use the acrylic tubing that I will already be attempting to bend in order to make the lily pipe/spray bar only in a larger diameter and bend it into a suction Mame style overflow as was posted above.

The only question I have about that is what are all those other pipes and tubes for coming off of the main largest diameter tube that is the actual overflow and are they important?

Edit: After looking at more pictures of the Mame overflow from other directions, I understand that the other little tube is the outflow.

I think it would be too expensive/difficult to make out of the acrylic, as I would have to get clear PVC fittings which are not cheap.

So I am then left with my original idea of essentially a noisy drain.

Edit #2 Hmm...If I used normal PVC fittings and painted them a bright white and kept them on the side of the tank instead of on the back, and put a bunch of plants in front of it, I might be able to live with doing it like this only using the clear acrylic for the part that is actually IN the tank.

http://www.nano-reef.com/forums/inde...owtopic=254404
Taari is offline  
post #15 of 21 (permalink) Old 08-09-2011, 12:25 AM
Planted Tank Enthusiast
 
Booger's Avatar
 
PTrader: (27/100%)
Join Date: May 2004
Location: Seattle, WA
Posts: 576
Quote:
Originally Posted by Taari View Post
The only question I have about that is what are all those other pipes and tubes for coming off of the main largest diameter tube that is the actual overflow and are they important?


Remember that the middle tube is the return. It is connected to the intake so that the overflow will restart automagically after a loss of power. When the power kicks back in for the return pump, that tube creates a venturi which pulls water over the edge. Cool, huh?

There are a couple ways to do this. For simplicity, I've also heard of other people skipping this step and instead using a [good] check valve.

Booger is offline  
Reply

Tags
None

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the The Planted Tank Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome