TWO OPTIONS OF HEATERS FOR AQUARIUMS OFFER OUR READERS. Uniform temperature in the aquarium keeps the water-filled Cycling or any other appropriate size camera. It is placed as shown in the figure.
S. KINDLER, Saratov
Heaters that are commercially available — with a filament and salt, or bulky, or too powerful.
“Semiconductor” heater:
1 — wire bracket, 2 — tube, 3 — sand, 4 — tube, 5 — resistor, 6 — power cord with plug.
Within a few minutes you can make a “heating” coal resistors type MLT, VS-2, MT-2, etc. with a capacity of 2 watts. They are inserted into the glass tube, the ends are attached to power cord with plug and close the vial stopper. The power of the heater can be more than 20 watts.
V. BEDNYAGIN, Novocherkassk
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FLAP INSTEAD OF GLASSES
When working with a rotating cutting tool it is recommended to use special protective glasses. Their role can play a makeshift shield-the intake is made of metal strips and thin sheets of Plexiglas.
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