How to drill tank to make ‘Reef Ready’

JosephM

Active Member
View Badges
Joined
Nov 22, 2020
Messages
240
Reaction score
141
Location
Lincolnton
I’m planning a 29gal reef tank with a 20gal long sump underneath. I was going to go with an overflow box but I’ve heard a lot of bad stories with those and some people recommended to just drill the tank. I can’t find anything exactly on how to do this. Anyone have tips or links to anything on how I can drill it to get water to the sump? Thank you!
 
AS

Doctorgori

Valuable Member
View Badges
Joined
Mar 18, 2019
Messages
1,680
Reaction score
1,705
Location
NE Ohio
I stink at searches but thats hard to believe. Nothing on Youtube? or Google?
I just did a quick look; Too many links to post. You shouldn’t have any issues, go slow. Eshopps sells a drill and instructions with thier overflow kit
 
OP
JosephM

JosephM

Active Member
View Badges
Joined
Nov 22, 2020
Messages
240
Reaction score
141
Location
Lincolnton
Just be sure the glass is not tempered. Decent diamond hole saw. Some overflows actually come with a hole saw for drilling a glass tank. Lots of water when drilling. Let the diamond saw and weight of the drill do the work. Very little added pressure if any!
Well I was going to go with a marine depot elite overflow box or just buying a simple acrylic overflow box and drilling the holes and putting my own bulkheads in but everyone is saying to just drill the tank. It’s confusing me because that is drilling the tank and I don’t know how the siphon can fail when there is no siphon and it flows into sump based on water level. Were people thinking I was going to go with a hob overflow box that does siphon?
 

Super Fly

Valuable Member
View Badges
Joined
Apr 19, 2018
Messages
1,117
Reaction score
787
here you go, I'd do it outside with garden hose constantly feeding it water though...
Like others said, just make sure its not tempered glass.
 
Aquarium Specialty - dry goods & marine livestock

Shirak

Well-Known Member
View Badges
Joined
Nov 3, 2019
Messages
641
Reaction score
341
Location
Thousand Islands, NY
Well I was going to go with a marine depot elite overflow box or just buying a simple acrylic overflow box and drilling the holes and putting my own bulkheads in but everyone is saying to just drill the tank. It’s confusing me because that is drilling the tank and I don’t know how the siphon can fail when there is no siphon and it flows into sump based on water level. Were people thinking I was going to go with a hob overflow box that does siphon?
So are you planning an external overflow with internal weir? There is no siphon. Water just flows into it and down the drain based on how fast it’s pumped back into the tank. HOB overflow with siphon has no holes in the tank. Flow into the tank must match the siphon, too little flow and the siphon could break and then the tank overflows. Too much flow and the siphon can’t keep up and the tank overflows
 
Last edited:
OP
JosephM

JosephM

Active Member
View Badges
Joined
Nov 22, 2020
Messages
240
Reaction score
141
Location
Lincolnton
BRS for a diamond drill bit. When you drill use a guide drilled into a 2x4 block or equivalent. Don't use pressure until the very end. It's really easy when you get through the first one.
Okay. I get the jist of drilling the hole. Once I get a hole drilled and bulkhead in place I purchase a simple overflow box from like Amazon and install it to the water level I want?
 

Shirak

Well-Known Member
View Badges
Joined
Nov 3, 2019
Messages
641
Reaction score
341
Location
Thousand Islands, NY
Okay. I get the jist of drilling the hole. Once I get a hole drilled and bulkhead in place I purchase a simple overflow box from like Amazon and install it to the water level I want?
Personally I would just get the whole thing all in one like the Fiji Cube overflow. Comes with everything you need. By the time you buy a box and separate bulkheads, internal drain of some sort and drill bit, probably be about the same cost.
 
BRS

Shirak

Well-Known Member
View Badges
Joined
Nov 3, 2019
Messages
641
Reaction score
341
Location
Thousand Islands, NY
Keep in mind... Need a decent size sump and check valve in the return line. Also don't put it way down on the tank. When the pump is off the return line will back siphon water out of the tank into the sump and overflow the sump. A check valve should stop that ... BUT They are not foolproof and don't count on them to work 100% of the time. If the return line is up near the top it can't siphon below a certain point.
 

shred5

5000 Club Member
View Badges
Joined
Jun 7, 2007
Messages
5,862
Reaction score
4,140
Location
Waukesha, Wi
I have drilled pretty close to a hundred of tanks I bet.

Make sure the glass is not tempered.
Go slow, have a guide or the bit will run all over and be hard to start a hole, use water as a coolant.

Biggest thing is do not put pressure on the drill, let the hole saw do the work. If you push when you get close to getting through it will bust out the glass on the back side and splinter. Also tape the back glass (opposite side you are drilling) with duct tape. Two reasons one it holds the water in and helps with busting out the back.


Also make sure you drill is completely level.

Also drill from the side the gasket will go on. This will be the smoothest edge. there is always a slight amount of splintering on the other side.

Make sure the clutch on your drill is set low. I have only busted one tank and this is how. The drill went through and the clutch was set to high and when I went through the drill went sideways just a hair and cracked the glass. If the clutch was set low the bit would have stopped and the drill would have just kept spinning.
 
OP
JosephM

JosephM

Active Member
View Badges
Joined
Nov 22, 2020
Messages
240
Reaction score
141
Location
Lincolnton
Personally I would just get the whole thing all in one like the Fiji Cube overflow. Comes with everything you need. By the time you buy a box and separate bulkheads, internal drain of some sort and drill bit, probably be about the same cost.
Okay thank you so much. I think that’s what I needed. How many gph should I shoot for? It’s a 29 gallon with 20long sump. My return pump is controllable but I wanna know what size overflow box. Would you say 400gph or the 600gph one?
 
OP
JosephM

JosephM

Active Member
View Badges
Joined
Nov 22, 2020
Messages
240
Reaction score
141
Location
Lincolnton
Keep in mind... Need a decent size sump and check valve in the return line. Also don't put it way down on the tank. When the pump is off the return line will back siphon water out of the tank into the sump and overflow the sump. A check valve should stop that ... BUT They are not foolproof and don't count on them to work 100% of the time. If the return line is up near the top it can't siphon below a certain point.
I was planning on putting it closer to the top with a jet return to act as a small powerhead is that fine?
 
Top Shelf Aquatics

Soren

Active Member
View Badges
Joined
Oct 2, 2020
Messages
296
Reaction score
494
Location
Illinois, USA
Okay thank you so much. I think that’s what I needed. How many gph should I shoot for? It’s a 29 gallon with 20long sump. My return pump is controllable but I wanna know what size overflow box. Would you say 400gph or the 600gph one?
More drain flow is probably better, since you can always restrict the flow with your return pump. I do not yet have experience, but I am researching for a 90-gallon reef I am setting up. If you oversize it too much, though, you may lower the water level in the overflow enough to not keep the drain pipe submerged and may create more sound.

If you use an overflow with more than one drain, you can use valves on one or more drain pipe to fine-tune flow for the drain as well as controlling flow with the return pump.

Also, technically a drilled overflow can still include a siphon, which is typically the main drain in a beananimal-style overflow. A fully submerged drain pipe will create a siphon that is silent as opposed to a drain pipe that water spills into and makes noise since the tube is not full.
 
OP
JosephM

JosephM

Active Member
View Badges
Joined
Nov 22, 2020
Messages
240
Reaction score
141
Location
Lincolnton
More drain flow is probably better, since you can always restrict the flow with your return pump. I do not yet have experience, but I am researching for a 90-gallon reef I am setting up. If you oversize it too much, though, you may lower the water level in the overflow enough to not keep the drain pipe submerged and may create more sound.

If you use an overflow with more than one drain, you can use valves on one or more drain pipe to fine-tune flow for the drain as well as controlling flow with the return pump.

Also, technically a drilled overflow can still include a siphon, which is typically the main drain in a beananimal-style overflow. A fully submerged drain pipe will create a siphon that is silent as opposed to a drain pipe that water spills into and makes noise since the tube is not full.
That’s smart. I’m going to go with the 600gph. Like you said it can always be dialed in with some valves.
 

Shirak

Well-Known Member
View Badges
Joined
Nov 3, 2019
Messages
641
Reaction score
341
Location
Thousand Islands, NY
The main drain line has a gate valve so you can let the water level in the overflow box rise slightly to keep a silent drain and not suck air in. The water level in the overflow will be slightly lower than the tank also. The emergency line is never restricted. 29 gal tank the 400 should be plenty. Even if you were running 10x turnover through your sump which is much more than needed these days with much better in tank flow pumps. If the price isn't much more then go bigger is ok too since you will control the drain line and if necessary the return pump.

Personally I would not count on the return line as a jet to make water flow in the tank. To be effective in that regard you need to move a huge amount of water through the sump. Of course how much flow you are looking for would depend on the corals you want to keep.
 

Soren

Active Member
View Badges
Joined
Oct 2, 2020
Messages
296
Reaction score
494
Location
Illinois, USA
The main drain line has a gate valve so you can let the water level in the overflow box rise slightly to keep a silent drain and not suck air in. The water level in the overflow will be slightly lower than the tank also. The emergency line is never restricted. 29 gal tank the 400 should be plenty. Even if you were running 10x turnover through your sump which is much more than needed these days with much better in tank flow pumps. If the price isn't much more then go bigger is ok too since you will control the drain line and if necessary the return pump.

Personally I would not count on the return line as a jet to make water flow in the tank. To be effective in that regard you need to move a huge amount of water through the sump. Of course how much flow you are looking for would depend on the corals you want to keep.
This confirms my research.
Thanks for adding that the emergency drain line is never restricted. I should have added this, since I meant restrictions only on the primary drain (and secondary drain, possibly though probably not necessary, in a 3-drain setup).
 
OP
JosephM

JosephM

Active Member
View Badges
Joined
Nov 22, 2020
Messages
240
Reaction score
141
Location
Lincolnton
The main drain line has a gate valve so you can let the water level in the overflow box rise slightly to keep a silent drain and not suck air in. The water level in the overflow will be slightly lower than the tank also. The emergency line is never restricted. 29 gal tank the 400 should be plenty. Even if you were running 10x turnover through your sump which is much more than needed these days with much better in tank flow pumps. If the price isn't much more then go bigger is ok too since you will control the drain line and if necessary the return pump.

Personally I would not count on the return line as a jet to make water flow in the tank. To be effective in that regard you need to move a huge amount of water through the sump. Of course how much flow you are looking for would depend on the corals you want to keep.
It’s about $20 more so maybe I will just go with 400 gph plus less room taken up in my tank. I’m not counting on the jet to do much at all just thought it would look better then a piece of pipe. 2- 480gph power heads one in bottom left angled up and one top right angled slightly down will be plenty correct? I will be using about 2” of sand
 
Corals.com

Do you own your DREAM CORAL?

  • Yes (please tell us what in the thread)

    Votes: 4 11.1%
  • NO

    Votes: 32 88.9%
  • Other (please explain)

    Votes: 0 0.0%

Online statistics

Members online
2,238
Guests online
6,145
Total visitors
8,383
Shop at PunisherCorals.com
Top