How big of a hole to drill for a 190 gal tank?

[Anonymous]

I think I need to drill my tank from the back. I want 2 holes. I need advice on how big the holes should be to put bulkheads in and what the water flow rate will be, if I use an Iwaki 100RLT for the water return.
Also, where should I drill from the top of the tank? The higher the better?? or should I guestimate to the amount that my sump can hold when let it drained? Should they be spread out on either side of the tank or place close together for convenence?

 

[Anonymous]

We have a 200 gallon tank that is driven by an RLT100 and it has two corner boxes each with a 1" bulkhead fitting for the drain. That will take a 1 3/4" hole. I would drill the same size hole for the return as it will give you more flexibility in the long run. Be real sure that the glass is not tempered or it will shatter when they stick a drill to it. If I were you I would drill the bottom and build corner boxes out of acrylic. It will work better in the long run IMHO.


[This message has been edited by Aquaman (edited 05 February 2000).]

 

[Anonymous]

As Aquaman said a standard 1" bulkhead needs a 1 3/4" hole to house.Meaning if you want 1" plumbing to attach to the bulkhead. I would recomend 2 pumps vers. the 100 rlt.It will cut noise,temp,and electrical use.The noise will be well worth the extra cost of the pumps.And cut about 1 amp out of use.A jap. 30 rlxt and a 20 jap is what one of my friends is running on his 150.It is the quietest(spell?)tank I have ever heard.And this tank has alot of stoneys.So flow is not a prob.

 

[Anonymous]

grasshopper: go to your LFS and check out the configuration of the "all glass" tanks with built in overflows in the corners. They work very well and may give you some ideas. I run one with an iwaki 70 return and do not push the capacity of the overflows, which are 1 inch diameter I believe. As far as height goes, you should have a little bit of freeboard (main tank storage space) in the event that you plug your overflows with algae or an anemone or something like that (believe me it will happen one day). Your sump will pump down until the pump starts sucking air, and the tank will increase in level just a bit (but won't overflow onto the carpet) if you do it right.

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I thought boats were expensive!
Dave

 

[Anonymous]

I'll throw my two cents in here.

I would personally go with 2 1.5" bulkheads. They require 2 3/8" holes. Why you ask? Better to go bigger than find out later you don't have enough.

I have a 1.5" on my 55gal. It is very quiet, and I attribute this to the oversized flow, their is no gurgling.

When in doubt, go bigger. If you check out my page, I have a DIY and pics of my overflow I drilled in my 55 gal, very easy. It is acrylic by the way.

You didn't mention whether it was acrylic or glass in the post. Important. Drill at least an inch or two from the edges. It you are putting elbows facing upward, you will need to put it further down anyway. with some more detail I think some of us could give some more info.

Good luck,
Keith http://web.tampabay.rr.com/lazydasy/keithreef

 

[Anonymous]

I would go with the 1 1/2" bulkheads if that is an option. It would really depend on how you plan to return water to the tank. If you are building two overflows and plan to drill 2 holes in each (one for water to the sump and one for return from the sump) then the overflows will have to be pretty big and take up a lot of space. In this case I would use 1" bulkheads. If you are drilling one hole in each and returning water by plumbing behind the tank then I would use 1.5" bulkheads.