question on over flow noise

[bananags]

hello,

i just finished drill 5 holes on the back of a 125gal tank (1/2" glass) for sump drain (1.5"), CL drain(1.5"), return(3/4"), close loop (3/4"), 2 more CL return over the top of tank power by ocean motion 4way.

making an overflow baffle box after i figure out this question: does the drain from back wall behind overflow box get noisy?

i read up on durso stand pipe etc..., but most set up for this is for drain to the bottom of tank, not sure what needed for my case

headless_donkey's tank has back wall overflow, not sure if he has any thing add in for noise or just the hole

thanks in advance, will post pics of the build up when i get a chance

Anh

Edited September 5, 2007 by bananags

[Headless_donkey]

I have a durso pipe in the overflow. I does cut down on noise because it give the air a place to escape. I almost did a standpipe because it would be smaller, but then I figured it wouldn't matter. Just a straight pipe will work, but if you don't have enough flow it is super loud and the water level in your overflow will go up and down. With a durso you can adjust the level of water in the over flow by varying how big the hole is in the top. You can also use a john guest valve to adjust. I was planning on doing this, but on our tank the noise is fine with the top to the durso completely open.

At first I was worried about coming out of the back wall, but it does not seem to make a difference. I chose out of the back so the sump could go the garage. I didn't want it under the tank.

BTW that sounds like a pretty cool tank. You should take some pics and show us. 5 holes in the back is brave and awesome.

[bananags]

hey James, do you by any chance have a picture of your final setup with respect to the durso pipe?I am not sure how to visualize durso on the back wall drain hole

I called Oceanic as you recommend, they said all of their 100+gal tank for sure has no temper back I ordered 38mm and 60mm diamond bit from ebay user "lau", from china, cost a few bucks, not worth mention (this is for 3/4"and 1.5" standard bulkhead)

here are some picture of my drill set up, since there is no way i can flip the tank to the side by myself

I set my drill for medium speed with lowest torque, but this is a Dewalt drill, so it's really strong

the 60mm only do 2 holes on 1/2"glass, with a little life left , i don't think i can make another hole, similar with the 3/4"bit, figured about 3 holes max using these cheap bit, even they advertise to drill 10+ hole, maybe on 1/4" glass ha ha

average 30-45 min per hole

i drilled almost non stop, just stop here and there to rest my hand ,check the depth, and slide the bit in and out to make sure the path is clean and straight --> see pic for my setup, constant water flow to the bit, does not even get warm and clean

word of advise, drill fast but don't push on the bit constantly, especially when close to get to the other, patient is virture, slow down as you about to get through to the other side, so the glass does not break at the opening. also, practice drill one hole on the spare glass so get the hang of it. I have never drill glass before, and it does not seem too hard at all, just 45min hole the drill is bit much.

there are many threads on RC on step by step drilling, just basically angle the bit and make a mark the glass so the drill does not slip all over the place.

here are some pictures of the final product

pix

cooling hole on top is the waste water sent from reverse osmosis setup, i just turn the valve 1/2 way on the RO unit and take the drain water to use as cooling water for drill

pix

picture showed the splash cover hold to the tank by masking tape, i soon realized that masking tape and water does not mix, so i use packing clear tape

pix

first hole, all the masking tape fall a part after the first hole done, next hole is much better, use packing tape instead =),

you can see the canopy i built on the other side of the tank ;-)

top left 1.5" is close loop intake, the bottom 2 holes are for a rock rack return, and 2 more return going over the top on both sides (was gonna drill holes on the back tank also, but lazyness may have given me a better option of return over the top), CL will be powered by iwaki 30 and OM quirt -->Goals: CL with low power pump install behind tank and total random water motion with the rock rack and 2 extra overtop return

(i got the rock rack idea from a few tank build thread on RC where water will be flow out from under the rock)

NOW, what is the proper way to install bulkhead, to silicon or not, maybe just a bit between the glass hole and the body of the bulkhead before secure the nut?

Edited September 5, 2007 by bananags

[bananags]

some more pix

Edited September 5, 2007 by bananags

[Headless_donkey]

That is sweet!

I just put an elbow on the bottom of the durso and came out the back wall. You are welcome to come to the house and take a look.\

You could also do an external durso if you have room.

From what I understand silicone on bulkheads is optional. The important thing is to keep the gasket on the "wet" side.

[bananags]

Thanks James.

I also found this stuff today, just information for others

Tank Overflows set up for drilled tank:

Herbie method - control the water level with ball valve, add a strainer for safety (ie snail guard)

Make sure water always above the drain, then no air --> no noise

http://reefcentral.com/forums/showthread.p...threadid=344892

or Durso setup -->allow noise to escape through the top

http://www.nano-reef.com/forums/index.php?showtopic=69372

This methods applied to both bottom and back wall hole

==> my case, the drain hole is deep enough in the tank, i can do with either method (with durso, i will have to extend the air escape pipe to over the top of the tank, or maybe a combination of them ha ha

Edited September 5, 2007 by bananags

[Entropy]

I DO NOT recommend using a ball valve on the drain. Basically what you are doing is matching the drains ability to drain to how much the return pump will pump. The only problem with that is that if something gets in the drain (and it doesn't have to be much) you slow the drain down further and flood the tank. I would only use this method if you have an emergency drain in reserve (example would be using both holes on a standard RR tank for drains instead of one return).

[bananags]

Thank you Entropy.

I understand the Herbie method and the risk of closing the valve to control the flow rate

The idea here is really matching the flow rate of the drain to the return pump, as long as the return pump is close to equal or faster than the drain, then you don't even have to close the valve on the Herbie method at all, or close it just slightly

(I am planning to use a powerfull pump Iwaki 40 forgot the exact XXXX model, the one with high head pressure rate)

And as long as the return chamber water capacity lesser than the tank highest water line when the drain valve is completely closed then there is no risk of overflow. (pump will shut off with sensor level by my own micro-controller unit anyway)

if the pump is faster or equal than the drain rate, then a T off needed at the pump output to reduce the flow rate and control the Herbie valve at the pump output w/o no risk at all

Thus, as long as I power loss test and valve shut off test and they both pass, then no risk of overflow (I will have the overflow box to contain the water level)

==> as long as the over flow box does not leak also =)

That bring to the next question, how do you use to glue the corner overflow box to the tank?

just use a lot of aquarium sealant? how about underwater epoxy (2 part liquid form) then aquarium sealant on edges, both side? what do you use?

I DO NOT recommend using a ball valve on the drain. Basically what you are doing is matching the drains ability to drain to how much the return pump will pump. The only problem with that is that if something gets in the drain (and it doesn't have to be much) you slow the drain down further and flood the tank. I would only use this method if you have an emergency drain in reserve (example would be using both holes on a standard RR tank for drains instead of one return).

Edited September 6, 2007 by bananags