Silent and Failsafe Overflow System
- Thread starter JohnL
- Start date
hello all,
I have read the original post a few times over and beananimal's explanation on his site.
I have a couple of questions:
1) Bean mentions that he originally had 1" bulkheads and then used a reducer with 1 1/2' standing pipes.
How much is adversely affected if one were to stay with 1" pipes? Would it just be a lower flow, or would it make it more difficult to create a full siphon? Would 1 1/4 bulkheads and standing pipes be all right?
I have the option of going forward with 1 1/2' bulkheads, but the piping will be quite large and the holes as well.
2)the original design used elbows with strainers, but i can't figure out where to get them, or how to make them.
3) I am getting a custom internal overflow box made (for a 125 gallon tank, and a full 72" coast to coast overflow seemed a bit much) and asked for dimensions of 24"L x 3" W x 6" H.
If i were to use a 1 1/2 inch bulkhead holes, and started 2.75" 'inches from the top, my bulkheads would fit, but only barely right? (the top of the hold would be 2" from the top and then there is the 1.75" rule).
Sorry if these questions have been answered ad nauseum, i have tried to read as much as i can.
Thanks!
I have read the original post a few times over and beananimal's explanation on his site.
I have a couple of questions:
1) Bean mentions that he originally had 1" bulkheads and then used a reducer with 1 1/2' standing pipes.
How much is adversely affected if one were to stay with 1" pipes? Would it just be a lower flow, or would it make it more difficult to create a full siphon? Would 1 1/4 bulkheads and standing pipes be all right?
I have the option of going forward with 1 1/2' bulkheads, but the piping will be quite large and the holes as well.
2)the original design used elbows with strainers, but i can't figure out where to get them, or how to make them.
3) I am getting a custom internal overflow box made (for a 125 gallon tank, and a full 72" coast to coast overflow seemed a bit much) and asked for dimensions of 24"L x 3" W x 6" H.
If i were to use a 1 1/2 inch bulkhead holes, and started 2.75" 'inches from the top, my bulkheads would fit, but only barely right? (the top of the hold would be 2" from the top and then there is the 1.75" rule).
Sorry if these questions have been answered ad nauseum, i have tried to read as much as i can.
Thanks!
I used 1-1/4" bulkheads and pipe. I reduced siphon to 1" pipe. It works perfect. My box is 18" long, 5" wide, and 6" high. With the bulkheads and elbows, the width was just barely doable (I used internally threaded bulkheads and threaded street elbows). You may not be able to fit the elbows with 3" width.
You can make the strainers using elbows on a table saw. I just used the elbows with no strainers and have had no problem.
I drilled my holes 4" on center down from the top. I have been very happy with this setup.
sleepydoc
Team RC
Depends on your system and how much flow you want. For most setups, a 1" siphon can easily handle over 900 gph. If you need more flow, you can use 1" bulkheads and upsize the pipe after the bulkhead like Bean did. Larger systems needing higher flows can benefit from the larger bulkheads, but most of the time you can use 1" bulkheads. The limiting factor ends up being the open channel standpipe. The amount of flow it can silently handle depends on the pipe, and a 1.25" pipe can handle significantly more than a 1" pipe.
Bean made them on a table saw, but actually doesn't recommend them. They're not necessary and are dangerous to cut if not done properly. You can buy strainers to put on your elbows, but if you design the system so the downturned elbows are about ¾" from he bottom it will keep most critters out and still allow adequate flow.
Have you already ordered your tank? If not, hold off until you have the system designed. The full coast to coast is generally recommended and is actually easier to install. 3" deep may be too narrow, depending on your plumbing. the 6" height should give you plenty of height.
See this post. A 1" Bulkhead needs a 42mm/1.65" hole, 1.5" bulkhead needs a 59mm/2.32" hole. the minimum is 1 hole diameter edge to edge, 1.5 diameters preferred. In general, the frames and plumbing requirements put you past these minimum requirements.
thank you sleepy,
Can i get one piece of clarification?
When you say below-
I bought diamond hole saw bits, and they come in sizes from 3/4, 1', 1 1/4, 1.5 etc, does this mean i need to find a different bit type of 1.65" in order to drill for a 1' bulkhead?
I understand the minimum distance between the holes and the rims looks at the diameter of the hole, is that what you mean in terms of calculating the minimum distances? You should use 1.65 instead of 1.5 for purposes of distance? or do I need to get a different drill bit sizes for my bulkheads?
I bought the tank and plan to drill the holes myself. As for a coast to coast overflow, i can't find anyones that would fit a 72" tank and the coast to make one seems to be exorbitant. I know that a longer overflow box means a better skimming capacity, but i figured 24' was pretty good. Should i go for longer?
for space saving, i think i am going to try for 1 1/4" bulkheads and standpipes.
Can i get one piece of clarification?
When you say below-
I bought diamond hole saw bits, and they come in sizes from 3/4, 1', 1 1/4, 1.5 etc, does this mean i need to find a different bit type of 1.65" in order to drill for a 1' bulkhead?
I understand the minimum distance between the holes and the rims looks at the diameter of the hole, is that what you mean in terms of calculating the minimum distances? You should use 1.65 instead of 1.5 for purposes of distance? or do I need to get a different drill bit sizes for my bulkheads?
I bought the tank and plan to drill the holes myself. As for a coast to coast overflow, i can't find anyones that would fit a 72" tank and the coast to make one seems to be exorbitant. I know that a longer overflow box means a better skimming capacity, but i figured 24' was pretty good. Should i go for longer?
for space saving, i think i am going to try for 1 1/4" bulkheads and standpipes.
uncleof6
Active member
No you don't. The standard size hole cutter for 1" bulkheads is 1.75", for 1.25" your guess as good as mine, for 1.5" bulkheads is 2.375". Space saving thoughts will usually get you in trouble, so beware of having those thoughts. Generally, if you need the larger bulkheads, it is most likely you would use 1.5". A little harder to find a hole cutter for 1.25" but they are around. Unless you are targeting 2000gph or above, there is no need to use bulkheads larger than 1". 1.5" pipe on 1" bulkheads will get you to 2000gph with a 36" drop.
woodnaquanut
Active member
Best to get the BH first. Depending on what material it's made of there are different hole sizes. ABS and PVC Sch80 are common BH material but I've also seen PVC Sch40.
You might want to check out BRSs website for sizes they carry.
For my 120G tank I have all 1" plumbing. My return pump is rated at about 950 gph with an actual flow of between 500 and 600 gph. The siphon valve is about half open.
thejuggernaut
Member
+1 on the BRS bulkheads. I think the ABS brand they carry is a little more heavy duty than some of the other brands.
uncleof6
Active member
They are no better or more heavy duty than any of the other thousand different makes and models out there....typical ABS bulkheads.
thejuggernaut
Member
I disagree. I once ordered the lifegard bulkheads and literally snapped the flange off 2 of the 1" bulkheads by hand tightening them. I said forget that and went to Hayward SCH 80. When I went to recently build my overflow box I called several places including lifegard. I wanted a lower profile bulkhead. They said they had switched from ABS to PVC to make them stronger. I ended up ordering several of the BRS ones instead, and the flange is thicker, the threads on the nut are deeper and more coarse. Lifegard may have changed them over the past 6 years, but back then they were not all equal.
thejuggernaut
Member
They are thicker and stronger, but they require a larger hole to be drilled in the glass.
uncleof6
Active member
The added strength of sch 80 is not physical strength really. I can snap a schedule 80 bulkhead just as easily as an ABS bulkhead. Most people don't understand the difference between finesse and brute force. Brute force will break either, and is totally unnecessary to get a good seal on ABS bulkheads.
The strength difference it in the pressure rating, which is unrelated to the "snapping" ease of the part. Also, it is not recommended to use threaded Sch 80 fittings together with Sch 20 fittings. It is a complete waste. For our purposes sch 80 is completely unnecessary.
I don't care really what folks want to use, but let's not stack the deck.
The strength difference it in the pressure rating, which is unrelated to the "snapping" ease of the part. Also, it is not recommended to use threaded Sch 80 fittings together with Sch 20 fittings. It is a complete waste. For our purposes sch 80 is completely unnecessary.
I don't care really what folks want to use, but let's not stack the deck.
Hey all, I am going to do this overflow but had a few questions first. My tank is a 40G Breeder with a 28G NRS-30 sump. The head height is gonna be anywhere from 30ish inches + or - a few. Would 3/4" pvc work or should I use 1" to be safe? I dont know if 1" would be too much flow for my size tank. 2) The T used can it be a regular T? I am having a hard time finding the sanitary T originally used any smaller than 1.5". 3) What size return pump should I use? I was thinking of using the Eheim Compact 3000 or the Sicce Syncra Pro 800 or 1000gph if yall think those will be too little or too much let me know, I would really like to keep the pump below $150... Also for the drains should I use 2 45deg elbows or a 2 90s?
uncleof6
Active member
Flow out of the tank, will always equal flow into the tank. Having more drain capacity than you have flow is far better than not having enough. 3/4" pipe is too small, and too easily plugged. 1" should be considered a minimum. As far as pumps go, you should be looking at the newer DC pumps rather than the old antiquated pumps you mentioned. Wanting to keep the price under $150, means you pay MORE long term, rather than paying a little more upfront in exchange for long term savings in energy cost. Use 45s not 90s.
sleepydoc
Team RC
Getting off topic for the thread, but check out this thread before purchasing a DC pump. They are turning out to be somewhat trouble prone. No clue if the 2nd generation is better or not, but there are newer AC pumps that are much more efficient and serve your needs as well.
+1 to uncle's comments on pipe size. Especially for the open channel. ¾" is pretty much useless for an open channel standpipe and won't give you much wiggle room to tune the system.
+1 to uncle's comments on pipe size. Especially for the open channel. ¾" is pretty much useless for an open channel standpipe and won't give you much wiggle room to tune the system.
thejuggernaut
Member
I don't really get the point of the DC pumps. Figure out how much flow you want and buy the pump that suits that flow range. Buying a larger pump and turning it down to where it falls out of its efficiency range is counter productive. You can't even use several of them on a set of closed loops to vary flow, because to my knowledge you can't hook them up to any controller, or even get the pumps to talk to each other. I really really don't see the point of running one on a skimmer.
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