Hi need advise.

[dbl]

Enlarging an existing hole is possible. It would be best to make a guide (can be made of a piece of scrap 1x wood). You drill the correct sized hole in the wood and find a way to hold it in place over your existing hole. It has to be solid so it doesn't slip while you're getting the new hole started. Go very slowly and do not apply access pressure. The weight of the drill is about all the pressure you want. It will take some time to get through the glass but it can be done.

However...if you've never drill glass before, I'm not sure I would recommend starting with this project. I personally still use a wood guide even with new holes, but that's just me. If you have a local LFS that would do it, I would recommend that route. Just my $.02.

 

[Bayareareefer18]

This is the bottom of the tank correct?

If it is the bottom most often these holes were drilled then the bottom was tempered or they drilled the tempered glass with special tools.

If you are talking about drilling the tempered panel of a tank I would probably have a glass shop do it.

It looks like those holes are drilled for supply and return of an external canister as it does not appear to have an internal overflow.

If it were me I would plug those holes and drill new holes in the back for a new overflow

 

[Justin4real]

I can confirm it’s the bottom of the tank and no it’s not tempered glass as I’ve contacted the tanks manufacturer and they dont use tempered glass on there bases on there Roma 240 tanks. But I know a friend just done the exact tank through the base over original holes.

I’m now looking at using the two holes on the right for some bulkheads that will fit and run them as returns. Just looking at cutting two holes on the left for two down pipes.

 

[Justin4real]

I have some spare glass I’ll try to cut before I go at the tank. As I’m a novice at everything. But I built a sump tank from scratch

 

[dbl]

...I’m now looking at using the two holes on the right for some bulkheads that will fit and run them as returns. Just looking at cutting two holes on the left for two down pipes.

I think this a much better idea.

 

[Justin4real]

It’s not perfect but it’s water tight. Also had t cut the glass from 18” to 15”

 

[Justin4real]

There some cheap bulkheads that will allow 32mm pipe via a 32mm hole. But others I got are 42mm wide which are the ones I was after using but hey it paid off to keep both set at hand.

 

[Bayareareefer18]

I can confirm it’s the bottom of the tank and no it’s not tempered glass as I’ve contacted the tanks manufacturer and they dont use tempered glass on there bases on there Roma 240 tanks. But I know a friend just done the exact tank through the base over original holes.

I’m now looking at using the two holes on the right for some bulkheads that will fit and run them as returns. Just looking at cutting two holes on the left for two down pipes.

That's good to know.

So far your down pipes what type of overflow are you trying to use?

Your holes may need to be in back not bottom

 

[MaddyP]

Welcome to the family!

 

[Justin4real]

I’m running a Herbie overflow as I want it as silent as I can get it. Also I’ve finished the cutting of the tank this afternoon.

Two test holes in some 12mm and away it was.

 

[Justin4real]

One emergency and one full siphon I hope as I’m going for round 3-5000l per hour with room for more running the maniflold. So I’m going for 8000l pump. To run it slower.

 

[Bayareareefer18]

One emergency and one full siphon I hope as I’m going for round 3-5000l per hour with room for more running the maniflold. So I’m going for 8000l pump. To run it slower.

Is there a built in overflow in the tank ?

 

[Justin4real]

No I’m adding this once I cut the base and added the pipes to tank. As the manifolds built under the tank and sump.

 

[Justin4real]

Making it from glass cut to order as I got ha6 silicone for marine tanks. The adding weir tops.

 

[Bayareareefer18]

Making it from glass cut to order as I got ha6 silicone for marine tanks. The adding weir tops.

Man sounds like a lot of work coming your way. Look forward to following.

Are you going to use black glass?

 

[Justin4real]

I’m in two minds about that one as plain glass is one thing but the back on tank been black since I had the tank. I would love to go blue all around but that’s not able to be done.

 

[Justin4real]

Unit prepped for the cutter tomorrow. Then it’s more plumbing before work. Then order some glass to size and a weir for the top of the glass. Just need to figure which ones to get.

 

[Bayareareefer18]

I’m in two minds about that one as plain glass is one thing but the back on tank been black since I had the tank. I would love to go blue all around but that’s not able to be done.

My thinking was to be able to keep pipes out of view as well as keep light out for potential algae growth

 

[Justin4real]

I will have a look but would like another colour. I’m looking at perspex to line the inside but unsure about it

 

[Justin4real]

That’s the solvent bonding done. Just the weir to do.