29 Biocube Mesh Top Project

[jimsflies]

Thought I would share some info from making the top for my 29 biocube (bowfront tank).


First I traced the outline of the front of the stock glass top on a scrap piece of plywood. Then I used the thickness of the frame to trace a line inside the outside trace of the top. Next I placed screws along the inside trace. This was to make sure the top would fit "inside" the rimstock. Next I put a strip of duck tape around the screw to keep it from scratching the frame.




Then with the jig made, I used a long piece of frame material so that I could get enough leverage to bend it. I then carefully started bending the frame into position so it fit the path of the screws. After it was bent accordingly, I cut it roughly to length but was careful to keep it a little long for final fitting. Then I started working on the corners...probably the trickiest part of the project. As you can see from the photo on the right, the angle was off (of course) after bending the top.



I used a propane torch to gently heat the corners so they could be bent and repositioned. Atter a couple tries, I finally decided the best approach was to super heat the frame then put the corner in place....this would have enough residual heat to allow the corner to be maleable.



Its hard to tell, but if you look at the photo on the left below, you'll notice how the plastic corner "kicks out" after being bent. This was going to be a problem for a good fit. I ended up adjusting my final cuts in the bowed part of the frame so that the angle of the plastic corner piece kept inline with the curvature of the bow. This was still going to be a problem for the corner to fit in the edge of the rimstock, but it made the front bow flow like it should...then I used a bandsaw and rounded the plastic corner pieces so they fit perfectly in the rimstock. I was able to do this by eyeballing the frame on the tank and then cutting a small amount off and trying again (trial and error). I then fit the mesh in like I normally would using the spline material and spline tool.



As you can see from the final pictures, the frame turned out pretty well....almost like it was made in a factory. There are a few stress marks in the bow from being bent...that straight aluminum really doesn't like to be bent like that. This project wasn't too hard, but having the right tools and the tank right with me to do the fit made it doable.

[demonclownfish]

very nice jim. if i wasnt going to be getting rid of mine soon id be all over this. r the dimensions of your tank different from the older BC 29?

[jimsflies]

I think the HQI model I have has a different rimstock than the regular biocubes. But I am not 100% sure of this.

[jimsflies]

I played around a little with the PAR meter (Apogee) today. This is the first time I actually measured the difference in light intensity with and without the mesh top. I'm currently running a Coralife 150w 14k on my biocube. I turned the pumps off during the measurement and set the light probe about 5 inches below water surface on a piece of live rock. With the mesh top on I measured ~315 umol m-2 s-1 without the top on the measurement was ~330 umol m-2 s-1. To put this in the perspective, I turned the pumps back on without the mesh top, the reading bouced between 290 and 310 umol m-2 s-1.

I think I can live with a 4.5% reduction to manage heat and keep fish from jumping.

I will take some measurements with the stock glass top for further comparison.

[ReeferRob]

Very nice DIY Jim.
Look forward to seeing more with the par meter.

[jimsflies]

I should be getting the new 20k XM bulb in a couple days...I'm interested to see how the PAR compares with the coralife 14k. I really miss my actinic lighting with this cube.

[jimsflies]

Okay, I measured the PAR again today....same readings as above, with mesh on and off...315 and 330 umol m-2 s-1, respectively. Also took a measurement with the glass top (clean) over the tank. The measurement was 299 umol m-2 s-1 with the pumps off. So, the mesh top provides better light penetration than a clean glass top.

Incidently, above water the PAR reading was over 1500 umol m-2 s-1. As soon as you go under water, the reading is cut below 400 umol m-2 s-1.

[MizTanks]

I'm lovin this project of yours Jim!