I just got a new tank ( 210g 84x24x24, not the DPA tank) and it has a few weird sized holes drilled in the bottom that I do not want. I can’t plug them with bulkheads so I have to cover them with glass and seal it with silicone. The tank already has a few holes that were covered this way. I’m guessing 1/2" glass would be best? The tank is made with 1/2" on the sides and 3/4" on the bottom, euro braced. Any idea what silicone I’d use for this? I really need to get a glass shop to cut me a few squares of thick glass, also have the edges polished. Where can I go to do that? Thanks everyone.
You can call Kaufman Glass on Quigley. thats where i get my acrylic cement. I bet you could even use 3/4 acrylic to cover the drilled holes. just glue them down with aquarium silicone too. its just to hold and seal. not really make a strength bond. i supose if you go with glass, you should use tempered glass for strength. but maybe not? one little hit on the cut edge would break the surface tension and shatter it. acrylic sounds good. if you can find some . less chance of a live rock banging it and cracking.
Hmmm so acrylic would seal ok? I just thought it’d have to be a glass on glass silicone bond. I agree that acrylic would be better, especially how you put it. 3/4 seems a bit thick though? I don’t think the bottom glass is tempered, especially having all these holes in it. I want to drill better ones for my overflow. I wonder if I am better off drilling over the little holes, making bigger ones to fit standard size bulk heads? Would that be possible Ken? I could have a closed loop on some, the overflow drains and returns on the others. That way I could probably take up all the siliconed glass piece coverings, I’d feel more secure that way. Plus I could go barebottom! I am just worried about having roughly 10 holes in the bottom of the tank, even though its 3/4" on the bottom, 1/2" on the sides and euro braced, should be ok? Thanks for your help.
I think I am going to drill out the holes to bulkhead size fittings. I will run dual drains, returns (with a check valve) and two closed loops for flow. Anyone see a problem in drilling a hole out to make it bigger? I don’t think the glass is tempered since it has so many holes drilled in it already. I have no experience with drilling glass, I know a few people on here have done it (Al), any pointers? I know take it slow, have the right diamond drill bit, and use a good water flow for coolant/removing chips. Anyone else have any suggestions for two CL pumps? Thanks.
Heres a quick pick, you can see the ugly glass plugs and all the little holes.
You can get glass cut at the Lowes in Middletown. They will cut their own glass for free.
le-frog
I assume this tank was not used as a fish tank but for a lizard or snake habitat. When this tank is full its going to weigh close to 2000 lbs. That’s a lot of weight to support with all those holes. (Even if you patch them.)
I think I am going to try and use all the holes before patching them, that way I can run it barebottom.
It has always been a fish tank, the tank is extremely thick and well built. The bottom glass is 3/4". I don’t see the holes being a problem, it’s been that way since day 1 and its pretty old, no issues. So am I good for cutting the glass? Just take it slow, steady stream of water, use the right bit (on a regular drill right?). I am really just worried about the initial drilling part, I don’t want the bit to jump around and mess up my whole or scratch the tank, just want a nice clean straight cut.
You should be ok. It might make it more tricky, but just take your time.
With glass that thick if you plan on using the cheap diamond holesaws(chinese) that we all use, your going to need more than one. Your probably only going to be able to drill 1 or 2 holes before the bit is shot. Yes, lots of water, regular drill, and some sort of jig to start the hole. You can make a jig out of anything that forms a 90 degree angle(wood, pvc elbow, etc). The holesaw will want to take off in only one direction. Lay your 90 degree jig in that direction and hold it firmly until you get the hole started. One the hole is started, you wont need the jig anymore. Use a decent drill on the highest RPM setting with low to moderate torque. Dont put any weight on the drill while drilling, just firm pressure. Let the bit do the work. It will probably take a decent amount of time with glass that thick, but should be straight foward.
The question i have, is if he was using the tank as a fishtank, how come you cant buy bulkheads to fit the holes? The sizes are universal, if he had bulkheads in them, you should be able to buy bulkheads to fit the existing holes. If they did not have bulkheads in them, then the tank did not have water in it. Maybe it was a herp habitat and he didnt tell you. Bulkheads add structural integrity to the glass, with out them the tank would crack eventually. I dont believe a tank that big would hold water with holes in the tank if they werent using bulkheads.
[quote=“logans_daddy, post:8, topic:956”]
I dont believe a tank that big would hold water with holes in the tank if they werent using bulkheads.[/quote]
I don’t care how thick the glass is. No tank is going to hold water with holes in the bottom of it. :-)lol
I agree, that’s why I suggested it was a herb habitat also
I know Al, got better in time with drilling holes. The holes in Craig’s tank look much nicer (cleaner) than the ones in mine…
It had a few canister filters on it. He gave me all the stuff for it and he has these little fittings with gaskets that sealed on the little 3/4" holes. Heres a diagram I made real quick to give you guys an idea of what I am working with.
You all could be right, it could be a rep tank, might not hold water, but theres only one way to find out! He had a sump with bioballs and everything plumbed into it, so I dunno?
I am a little confused on the “jig” when starting to make the hole?
Also I plan on buying the bits from glass-holes.com Are they cheap? I will probably get a few extras anyway, I do not want to mess this up, I have one shot at it, otherwise I’ll definitely have a reptile tank!
Thanks for all the help everyone.
How about laying another piece of glass inside the tank. All those holes even in 3/4 inch glass would make me nervous. It may hold water today but as things settle and they will and a twist develops this thing could let go big time. Maybe just a 1/2" piece inside and sealed to the sides then install your bulkheads. You don’t want 200 gallons of water on any floor.
Mike
I know Al used a pretty fancy jig that he purchased somewhere. Im sure he can give you the info. Basically, when you start the hole, the bit will skip and slide all over the place. Its almost impossible to start a hole without a jig. What ive always done is this. I use a 90 degree pvc elbow. I mark the posistion i want to drill, then i hold the elbow laying on its side against the holesaw. The holesaw will pull away in one direction only. Put the elbow so that it holds the holesaw in place. Gently hold the elbow with your hand as you start the hole with your other hand. Once the hole is started you can remove the elbow. It simply allows you to start the hole without having the bit skip across the glass.
I don’t know if laying a piece of glass down inside the tank will add much strength? Plus there is no way to get a piece that big inside the tank without taking it apart. Will drilling the holes out a little bit bigger and adding bulkheads help or will covering the holes over with glass be stronger?
So the jig can only be a 90 degree PVC elbow? I understand the concept of it, but just didn’t know what jig to use. I guess the tricky part is finding out which way the bit is going to jump.
no, you can use anything. thats just what i have used with no problem. Ask Al to show you a pic and give you info on what he used.
I personally feel that simply laying glass over the hole with out filling the hole will create a weakpoint structurally, but im not an engineer.
If it were my tank, i would take some 3/4 inch plywood and try to cut it to the exact size of the holes. I would fill the holes with the would as well as some sort of sealant. I would then take a much thinner piece of glass, maybe 3/8, and cut a square 2 to 4 times the size of the hole. Lay down a bead of silicone along the perimeter and be done with it. The plywood will provide the structural support. The silicone will act as a gasket, and the weight of the water pushing down on the 3/8 will keep it sealed forever and a day. This is similar to what they do with plywood tanks when adding a viewing pane.
Using this method, you could paint the bottom of the tank black. Paint either the plywood black or the underside of the 3/8 black and still be able to go BB without too much of an eyesore. Not to mention that this would be the easiest and cheapest thing to do. The glass you can have cut for you and the cost of the glass will be cheap. The plywood can be bought in project sizes. Make a template of the holes out of rigid stock paper, transfer to the plywood, and usa a jigsaw to cut out.
At the end of the day, the only thing that matters is that you have a big tank for that passer and moray without breaking the bank.
That’s a lot of holes. you can cover holes with a square of acrylic and silicone, which will hold water and the weight. but you cant repair the strength of bottom glass which is reduced with every hole, or enlargement. too many are lined up making potential break lines. I wouldnt feel too good about drilling more holes in that one.
the best way to make a templet is to use a piece of plywood drilled the same size of hole saw you are using. use rubber ended quick clamps to hold plywood templet over hole you need to enlarge. you will be placing hole saw through plywood jig to keep bit from moving and boucing around. this will allow you to drill over a hole already drilled. just position bit for your needs and try to have bit cover all edges of other hole. we use this method all the time drilling over predrilled holes to enlarge them. hope this helps. and i agree with kaptken about the strength issue i would try to use holes if you can and only enlarge the holes if you need them. the more ya remove between holes the more likely too crack.
First off, thanks for all the replies and advice, very helpful. I’ve decided against the CL for many reasons. I’d have to drill the holes bigger, which would make the tank weaker. Also the cost of not only the equipment, plumbing but the electricity to power a big pump compared to say 4 K4 powerheads just doesn’t work out. I think the plan is to uncover the back 3 1.5" holes, have the 2 corner ones for my drains and the middle for a return.
So say I get 1/2" squares and cover up the rest of the holes, silicone them down, they won’t leak, but will they hold as far as weight and not break? I don’t know if the plywood would help or not. Also I’d need to cover the whole bottom with glass to make it a BB, that would be expensive and don’t know if it’d work. Couldn’t do it in one piece since I couldn’t get it thru the top of the tank. I think its probably best and easiest to just patch the holes not being used and put sand over them, I just hope none of my fish move the sand enough to expose the edge of the glass, potentially cutting themselves.
So now that is hopefully settled, “hopefully”, I can focus on the drains. I don’t have an overflow box, so I am just going to buy gray pvc tubing, and run a drain pipe, but have rocks drilled around it, so hide it. My problem comes with the top where the water goes in, I can’t run a durso style, it’s too big and can’t be covered. Anyone have any ideas on how to make a quiet vertical pipe drain? I’ve seen it done before on a 40b, getting oversized caps, still that would be hard to cover up.
Also, how much flow could two 3/4" bulkheads handle at the bottom of the tank? I was doing some reading on flowrates and I got confused about the whole height issue and how it plays a factor into the flow rate. My return pump will probably be putting out about 600gph after head loss.
So say I get 1/2" squares and cover up the rest of the holes, silicone them down, they won't leak, but will they hold as far as weight and not break? I don't know if the plywood would help or not. Also I'd need to cover the whole bottom with glass to make it a BB, that would be expensive and don't know if it'd work. Couldn't do it in one piece since I couldn't get it thru the top of the tank. I think its probably best and easiest to just patch the holes not being used and put sand over them, I just hope none of my fish move the sand enough to expose the edge of the glass, potentially cutting themselves.
The plywood(or something similar) woudl be integral. Think of it this way. If you take a piece of 1/4 glass and lay it across an open frame, meaning only the perimeter is supported, how much weight would it hold before it cracked? It would cause undue stress on the patch. Now imagine that you plug the hole with the plywood so that the bottom of your tank is flush with the plug. Lay the same piece of glass on it now and there will be no stress whatsoever from the water. I can put a piece of 1/8" glass on the bottom of a swimming pool, it wont crack from the weight of the water. Filling the hole with something to provide structural integrity is crucial. After that, you could honestly get away with a 1/8" piece of glass with a gasket. Or you could simply epoxy the plug and glass. There are a bunch of things you can do to run BB. It woulnd be pretty up close, but no one notice if they werent looking for it.