Ejls,
First of all, to answer your questions:
I don't remember exactly what brand my pump is, but I will check when I get to work. Do a search on Ebay for "metering pump" or "dosing pump" or "diaphram pump" you will see some different models come up like "Prominent" and "Milton Roy". Start searching them out at their homesites and find what output each model is rated at. Estimate (or measure) how much your tank will evaporate in a day and then find the pump that comes closest. The difficulty will be to find a pump with a very low output (most of them will be overkill). You will find that generally the pumps that have the highest pressure rating will have the lowest outputs. They are all very adjustable and any pump will work but you might need to turn it down, or even use a timer so that it only runs (doses) for part of the day. If you have your heart set on having the pump run continually, you will need to buy one of the LCD display models that give you the option of switching from "strokes mer minute" to "strokes per hour" - normally a dosing pump will stroke once per minute on the lowest setting. But that is still 60 strokes per hour. To give you an idea, my dosing rate is currently set on 12 strokes per hour!
Here is an example of a pump that would work (but that price doesn't work):
http://cgi.ebay.com/LOW-FLOW-CHEMIC...865704858QQcategoryZ46547QQrdZ1QQcmdZViewItem
These pumps are hard core, for use in labs and manufacturing - they are built to way!!! higher standard than any piece of fish equipment I've ever seen. That will lead to peace of mind - but also an empty wallet...
As for overheating - you will not have a problem as long as you don't try and put your lighting in a canopy or close it in. I have always said (and no one really listens), that metal halide is the coolest form of lighting! This 2gal tank with 70watts of halide (35w/gal) is way cooler than my 90gal tank with 220watts of power compact (2.5 w/gal)! The reason for this is, in order for fluorescent lighting to penetrate, it has to sit right on top of the tank - thereby blocking the flow of air. My halide sits about 7 inches from the top of the tank and none of the heat from the bulb makes it to the tank; infact, if you hold your hand at the water surface the only warmth you can feel is from the radiant energy (like the sun on a warm day). One of my submersible lights has burned out in my 'fuge and since then my temp has only been 74 degrees - I am looking forward to when the replacement bulb arrives so that I can bring the temp up a bit.
I hope this answers your questions!
As for your project of a cylinder tank on a turntable - I am really excited to see how it goes!!! Infact my current setup is only a concession that I made to my wife - my real plans were an acrylic cylinder tank on a motorized turtable that slowly rotated by its self.
My plan was to have the tank on a table attched to a lazy susan bearing (
http://www.awsc-online.com/ContentL_a.htm) which was also connected to a hanging basket or harness under the counter. I would bolt a servo or stepper motor (
http://www.alltronics.com/stepper_motors.htm) to the underside of the counter and have the driveshaft sticking up through a hole to make contact with a spur gear (
http://www.qtcgears.com/RFQ/default.asp?Page=../KHK/newgears/KHK114_2.html) attached to the bottom of the turntable. The motor would rotate the lazy susan w/ tank and also the basket underneath that held the cannister filter. The electrical cord for the cannister filter and pond lights would stick out of the bottom of the basket where it would be connected to my power sourse via a rotating coupler (
http://www.power-delivery.com/photos.php),.
As I said, a rotating cylinder tank was my dream and I am really excited to see how it works out for you. If you have the werewithall to make it motorized, well then I hope some of the research I did can be put to good use
. I think you will find that a rotating inlet/outlet plumbing connecter will be very difficult (if not impossible!). Your best bet is to have the whole setup turn and only worry about rotating your power sourse. In that case, the electrical coupler will probably still be your answer whether you go motorized or hand-powered.
I look forward to seeing how it goes!
Sorry for any mistakes, I was typing in a frenzy. And sorry for the long post everyone
- Chad
