Pre-drill back or bottom of tank?

drjosay

Member
hey guys,
I seem to keep getting confused on this topic. Could someone explain why it would be better to have the back of the tank drilled rather than the bottom? I read in a couple of places that if you drill the back of the tank, it would prevent a flood in case of a power outage. I'm not sure I quite understand how it would be any more advantageous than having the bottom of the tank drilled. Wouldnt the water level in the display tank continue to drop until it reached a level below the overflow boxes in BOTH cases?? If I'm missing something here or if somebody could explain this to me, I'd really appreciate it.

Thanks!
 
There is no difference in drilling either the bottom or the top of the tank. The water will continue to drain like you said until the water level reaches the drain. I like drilling tanks on the backside better because it saves tons of room. I hate reefready tanks because the overflow boxes take up a lot of room and looks ugly in a nice reef tank.

Also most tanks are tempered at the bottom so you can't drill it, on most tanks 180 gallons and up you can drill the bottom but it is really thick especially on a tank like a 265 the glass is a 1" on the bottom.
 
Aqua-World,
When you say that it saves tons of room, what do you mean by that? I would think you would save more room by having the bottom drilled; then being able to have the back of the tank nearly up against a wall. Wouldnt having the back of the tank drilled cause you to keep it a certain distance further from the wall?
Or were you merely stating that bottom-drilled tanks require the internal overflow boxes, and thats what takes up all the room (meaning inside the display tank)?
 
Aqua-World,
When you say that it saves tons of room, what do you mean by that? I would think you would save more room by having the bottom drilled; then being able to have the back of the tank nearly up against a wall. Wouldnt having the back of the tank drilled cause you to keep it a certain distance further from the wall?
Or were you merely stating that bottom-drilled tanks require the internal overflow boxes, and thats what takes up all the room (meaning inside the display tank)?
 
He meant that the overflow boxes take up a lot of room in the tank. My point is that it's only so much safer if you do it wrong, because if the overflow leaks (and plexiglass doesn't bond as well to silicon as glass) you wouldn't know it until the power failed. If it's done right and you're lucky and nothing ever fails, there's never a risk. The reason I'd prefer a drilled back is because Murphy's Law always seems to come into play, no matter how many precautions you take or how well you try to do something :)
 
I've always liked glass overflow boxes built to accommodate the 2 or 3 holes in the back of a tank. They're transparent and a lot less intrusive into your tank area in general.
 
Just don't count on too much surface skimming... which IMO is one of the main advantages of a coast to coast or horizontal overflow located on the back of the tank.

They also take up as little or as much space as you want... here's the 220 I drilled 11 holes in then ended up selling. :rolleye1:

220calfo8.jpg


front2-1.jpg


Finished product... Wait... where'd the overflow box go!?!?! :lol:

finfin.jpg


I also did the same thing on my 90g tank... I absolutely love how this overflow system functions and plan on using it on all my future tanks.

TR03.jpg


6542.jpg
 
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Thank you. I didn't paint it. I had a piece of acrylic cut to cover the front pane, then clamped it and glued it in place with silicone.

The 90:

acrylic1.jpg



cover1.jpg


The 220:

Guard2.jpg


fin3.jpg


fin2.jpg
 
WOW, nice job T. I really like that. I should try to do this on my future tanks.

(nice meeting you BTW. I hope everything went well on your long drive)
 
Tom you can find the complete overflow plans on my website (and the silent and fail-safe overflow thread here at RC).
 
<a href=showthread.php?s=&postid=14069136#post14069136 target=_blank>Originally posted</a> by TomNeely
WOW, nice job T. I really like that. I should try to do this on my future tanks.

(nice meeting you BTW. I hope everything went well on your long drive)
Thanks... yeah it was definitely a long trip, we ended up getting back at like 3am. :lol:
 
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