March 4 2011

Good progress

Some progress has been made the last months. Almost all the equipment and chemicals are now bought. The nutrients, except from the silicate, are secured. I am depending on Seachem Flourish for most of the substances. All the parts for the CO2 system are in house, including a 10 kilos bottle. Should last for 4 years+. The stands are done. The tanks are insulated with styrofoam and double glass, and drilled. The remaining job now is to set up the hoses, with hose insulation, ducts and pumps. Shelves for electrical cables and timers, chiller, skimmer with furniture, lighting and other smaller thing. Then a test with fresh water is in place.


The stands are done with my simple ordiary carpentry style. The one for the plankton growth tank is a bit taller so that it can overflow down to the display tank.

Working on the display tank stand. The taller refugium stand in the background.

Test tank

I decided to test double glass and hole drilling this old 30 liter.

Test tank.


This was my first drilling of a tank. Obviously I tried the test aquarium first. People say it is easy if you do it right. It went pretty much as expected. The hardest part was to get started. I did that by holding the drill bit at an angle and touching the glass gently to make a dent in it. Then reduce the angle gradually to get an even hole. I used little to no pressure and speed of about 1.5 rounds per second.

The setup. Playdough to make a pond of water. Ductape below to catch the glass piece. The best is if you can clamp something hard underneath. That prevents damage to the lower edge of the hole.

Here I am through. I changed water a few times during the drilling. The playdough was water soluble so it started leaking :-). Not the best material.

Not a work of art. But it was my first. Some damage to the lower edge of the hole. But the bulkhead gasked covers it.

Double glass

I am experimenting with making double glass. The basic idea is simple: Buy a thin glass sheet the size of the side to insulate. Then glue it outside with an air tight spacer and place moisture absorbing material in the void. But in practice it is more complicated. For example, what should I use as a spacer? I don't know any plumbers or construction workers, so I don't have access to free scrap materials. I kind of depend on the stuff I can find in local stores. I didn't want the distance between the glass sheets to be too great, so I decided to use a spacer of 10 mm. The ideal object for this task would be 10 mm square tubing. Either of plastic or aluminium. But it seems like such things simply aren't for sale here in Bergen. The closest I got was in am RC model store where they had 10mm styrene tubing. This tubing was very expensive, and they had little of it, but it was at least possible to join the short lengths together with tube of a smaller dimension. I only got enough for one side! But that was enough. I made the other spacers of polyurethane foam that is made for use as sandwiching material in fiberglass or carbon fiber construction. It was easy to cut and much stronger than regular foam plastic.

10 mm styrene square tubing.

Receiving glass sheet from a local shop. They cut them exactly to size for you. 4mm thickness. Very cheap.

The first thing you must do with these sheets is to sand the edges, because they are razor sharp. I used wet sanding paper. It works well and doesn't make any dust in the room. For rounder edges a belt sanding machine can be used.

Cutting the 10mm polyurethane sheet to make spacers for the sides where I didn't have tubes.

Polyurethane and tubing spacers.

Painting the spacers on the inward facing side to get uniform coloring.

Using a needle to make holes in the inward facing side of the tubing. This enables the desiccant in the tubing to dry the air in the space between the glass sheets.

Glueing the spacers to the outer glass pane with black MS polymer based glue. Use only one bead of glue like shown. Don't try to smear it out with you finger. It will only capture air pockets.

Making sure the visible edge is straight. Otherwise it looks ugly. Kind of tedious work with a knife blade and tissue paper. I should have used masking tape!

This is the critical portion: Cleaning the glass before sealing up the window. I used glass cleaner first, then acetone. Dust and grease are the two main enemies. The glass looks clean, but if you shine a flashlight at it you can see how dirty it really is ;-p.

Notice the 5 by 10 mm groove all around the window. I filled this with glue to make a final seal against moisture.

Cleaning up final seal. After this it was left to cure for several days.

Actually, I didn't seal it completely. I left this opening to fill in the desiccant after the the major portion of glue was cured.

Filling the tube with silica gel desiccant. Aquarium stores sell it for use with ozone generators. After the tube was loaded I put a plastic piece in the hole to protect the glue and desiccant from each other and then sealed with glue.

Testing double glass. Not very good test since the air in the room was too dry.

A little mist forming on the non insulated side.


I don't know what to call these in english, so I'll just use the word "tray". One of the issues I imagine with a phytoplankton refugium is that algae that are attached to the walls will have a great advantage over the free living ones, since the attached ones will never be washed out. Also, anything from bacterial films to animals attached to the walls will be able to capture and feed on the phytplankton, thus limiting the function of the refugium. So the walls and bottom must be kept clean at all times. That is hard to do in a refugium where vacuuming can be done! So I decided to make these inlaid trays from acryllic. With these I can simply take out the walls and bottom and scrub them, with very little effort. The acryllic was expensive, but now I got experience with the material. It is fairly easy to work with. Sadly I wasn't able to obtain a good glue locally. But I hope that my MS polymer will do the limited job of holding the trays together. If it doesn't it won't be a major problem.

I ordered this piece from the glass shop. 4mm white acryllic.

This is the setup for bending. Heat with hot air gun and just bend. It was harder to bend the small handles at the ends because there was no leverage.

Ouch, leverage is good. But be careful, it's brittle.

Finished product, in the phyto refugium.


The tanks are entirely insulated with 20 mm styrofoam. Except from the front of the specimen holding tank which has double glass.

First put on some glue...

... then smear the glue out so that the foam gets good contact with the glass. Seal well along the edges.

Further plans...

There is still some way to go before water test. I am working on the plumbing right now. Fortunately I have all the pumps needed. At least I think so. It could be that I have to buy another pump. After that the CO2, electrical, air system, and the like must be set up.

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