I need help with drain heights

[mudbuttjones]

hey everybody,

I need some advice. I'm drilling my brand new 125. I'm putting 3x 1" bulkheads along the top trim. I am doing a custom 3d background that hides the overflows and some other stuff. I really don't want to "dry fit" and test the plumbing on the system, break it down again and then do the background fiting, painting, etc. I'd like to do it in one shot and avoid moving/draining the tank a few times. I have 2 small kids and work 60 hours a week. I'm lucky to get a few hours a week for this project, so any time saved equates to this project taking weeks vs months.

my question is, how high should i drill for the bulkheads? I normally put them a few inches below the rim and use an upturned 90° with a strainer on top.

would you drill the holes higher up and mount the strainer directly to the bulkhead? it's a 1.75" holesaw so I should be at least that far from the end of the glass correct?


looking at my 90g with an integrated overflow, the teeth of the weir are almost level with the plastic trim. should I kind of follow this spacing for the 125g?


i just want the water level to be hidden behind the plastic trim and I don't want it to overflow on the floor (obviously)

at head height I'll be pushing around 1000gph through the display

in addition to the 3 bulkheads I'll be running 2 drains lower in the tank similar to this, but drilled on the back pane as well. this spacing is not as crucial. I'll be able to adjust this outside the tank.

 

[markstrimaran]

Probably better to error on drilling to low than to high.
I like to leave room for threads on a pvc pipe to be adjustable, up and down a bit.

 

[markstrimaran]

If your flowing a full siphon and the top bulk heads are for skimming only, and emergency.
I would leave the top of the weir about 3/4" below the inside lip of the plastic trim. About 1/8" above the bottom of the plastic trim. With the ability to screw down the overflow wier caps.

 

[mudbuttjones]

the lower drains are just to pull stuff from lower in the water column and eliminate dead spots. all 5 drains are vented (open channel) 1" drains

 

[duanes]

http://s70.photobucket.com/user/dstuer/media/Drilling/018_zps0675de85.jpg.html

I like to drill high enough to leave a few extra inches near the edge, and allow for a PVC elbow,but not so close to the top of the glass to allow it to crack in the process.
And although most people consider feces and detritus to be the worst stuff. Actually the things that can degrade water quality most, collect at the air water interface (surface).
Oil floating on puddles is an obvious example, and like oil, proteins tend to head to the surface.
All the big heavy stuff is best vacuumed out with water changes anyway.
This is one of the reasons protein skimming is used extensively by reef keepers to keep water quality high.

Its the invisible stuff that creates problems, and in the video below you can see it become visible, because it is being fractionated (skimmed with fractionation) out of my fresh water pond.
koi pond fractionation

 

[markstrimaran]

So each drain, will be flowing at 200 GPH. This drain is 1" and flowing at about 150gph. The pipe was not cut straight, so the flow is uneven around the circumference.
So you need to know how high the water meniscus, will build above the tube. At 400 GPH, assuming some emergency redundacy.

 

[mudbuttjones]

I decided to order 3 small overflow weirs to silicone directly to the back of the tank. they are small like 3.5x5" it was $59 for all 3 on ebay.

i can mount these high in the tank and notch them out some more with a rotary tool if the water level is too high.

these overflow boxes should fit in nice behind my background.

thanks for your replies.

 

[coryjac0b]

I would look at the "Bean Animal" style overflow. Once it is tuned with a gate valve it is silent and fail safe.

I used this style overflow with a bean animal overflow and it has worked flawlessly for more than a year.

 

[badassissimo]

What would be the issue with the bulkhead being too low?