….Did some more over the weekend!
I finished off the light support and tested it out. It held the light no problem. I hooked up the ballasts and fired them up. Light definitely makes the tank look bigger. I’m still thinking about plants/layout. I’m not sure if I will need more than 2.25WPG.
Plumbing – well the 25mm bulkheads I ordered had massive flange’s and the holes drilled where too close together for them to fit so I had to cut them down. I used the Angle Grinder….. Yep, I highly don’t recommend this one, but I didn’t have a hack saw and was too impatient to go to Bunning’s.
The bulkheads are not made with Poly, they are NyGlass (which is a compound made from Nylon and Fibreglass). The place I bought them from says NyGlass is much stronger than high density poly and almost as strong as steel. So like Brass maybe? Well anyway, by the end of cutting I had melted black NyGlass all over the place. Please excuse my bad cutting when you see it in the pictures. I held the bulkhead in one hand and the grinder in the other…..i live on the edge sometimes. At least they will be under the substrate.
The tricky bit will be the bulkhead nuts - Cutting them so I am able to screw them on. I will do that next weekend.
The holes in the tank are also right on top of the cabinet cross support beams so I had to do a bit of modifying apart from just cutting the holes in the cabinet lid. I will show pic’s of that later when I’ve finished. It looks a bit messy at the moment. I’m told it won’t take much from the strength of the cabinet and will still hold. One of the beams I have cut completely through so the bulkheads can come though. I will screw in another piece of sized wood once I have the plumbing finished.
Firstly congratulations on the lighting hood. Looks great. I've recently completed one too. Its a great feeling when you get it up and running.
I noticed your pipe penetrations are close together, so much so the flange bolts needed trimming to get them to sit together. Couple things to be aware of, the flanges provide the seal between the glass (including hole) and the plastic pipe. I would strongly suggest (if it's not too late) to use lots of silicon particularly around the centre stand pipe in the photo marked 'Left Hand Side Plumbing'. Another thing you need to be aware of is that the glass between the holes is the weakest point in the tank base. If you are going to have the base crack, this is where it'll happen. Last thing you need is 400l though the dining room when you're not home, and dead fish. The holes are cut so it's too late to spread them apart, but I would pay particular attention to how you plumb pipework beneath the tank so that you don't impose bending moment loads on the joints. Over time this could result in cracking between holes. Hope this helps.
Yeah, to be honest. I am a little nervious. I was thinking about spending the money and buying different bulkheads with smaller flanges. I then compared the flange of the bulkheads to Lifegaurds air control unit that im placing off centre. Now that air units flange is quite small. Probably about 7mm wide. Then i looked at my bulkheads and thought that i could cut them down to fit. The cut part will hopefully be supported by the untouched area of the flange. The gasgate of the middle bulkhead is also uncut - so the bulkheads flange on either side will also press down on the centre gasgate. I have not silconed the bulkheads yet but when i do i was going to silcone the gasgate down as well as place a layer around the 3 bulkheads where they finish/touch the glass. Kind of like a border. What are your thoughts on this?
The tricky bit is the bulkeheads Nut. The flange on this will have to be shaved all the way around for me to tighten the nuts. The support beams are in the middle of being modified so that the plumbing does not touch and cause stress on the thin layer of glass between the holes.
I can see you've been to some effort with the setup and it looks great, particularly the light. Sometimes when you've come a long way, waiting a little longer can be hard but worth it. If it were me, I would look seriously at getting new holes cut. The recommended seperation between holes in glass like this is about 100mm. For a 1" hole, you can buy the bulkheads from Bunnings for $10each (Hansen). I would look at getting a tank manufacturer to glue glass plates over two of the three holes in each corner and cutting new ones.
I would also be nervous about the setup, particlarly, as you point out, the nuts beneath the tank will need substantial modifications to the flanges just to do up the nuts. Overlapping the gaskets comprimises the seal for the other two flanges as they would not be flat against the glass. To give you an idea what I have done after some research into cutting glass, I have attached a recent shot of the tank I've been doing up.
Just to add - the gaskets wont be overlapping. I have carefully cut the outside bulkheads gaskets so that the middle bulkheads travels under the outside with no problems.
I do have 100% confidence in the tank builder. My frame of mind was that if the bulkheads are siliconed and tightened properely (i think hand tight with a extra quarter turn?) then the strength wont be comprimised?
The hand tight with the extra quarter turn is my understanding too, but this would be based on the flanges not being modified. If you're going to go ahead with this then for another $20 (3 tubes) I would use lots of silicon on the inside of the tank. Maybe consider half filling the tank with water and check for leaks before you put substrate etc in there and fill it up all the way.
Another thing, I would make sure the styrofoam is new and thick so that any minor ridges in the base of the tank stand (beneath the glass tank) do not impose any point loads onto the glass. The main cause of cracking in the areas between the holes will come from an uneven base resulting in higher load concentrations in various parts of the glass tank base.
Yeah im pretty confident in setting it up now. Ive had a chat and have pondered the plumbing. Silicone does pose a risk as the double gaskets are designed to keep a tight seal and sometimes silicone can disrupt this. The flages although cut, are still longer then most aquarium made bulkheads so the seal will still be tight. In saying this - i plan to use minimal beeding on the nut side of the bulkheads with reinforced silicone on the side of the top flanges. The top part siliconed will be filling any gaps between the flanges and where the flange meets the glass. So it kind of forms a pre seal but the gaskets form another seal.