Heater Questions

[Nickoli]

Hi all,

I have a few heater related questions.

When I had lager tropical tanks, I would usually run with the single largest heater I could, but often that was enough and I had to use two heaters due to tank volume. This worked fine and dandy, but it ended up being that one heater was doing most of the work. It was hard to set two at the same time, and time consuming.

I was wondering if there is a thermostat type device that will monitor temperature of the tank, and turn the heaters on and off accordingly?

Next question, for a larger tank, would it be better to run a heater in a sump tank, or in line with a pump?

Finally, what are the largest watt heaters (of any type) you can find? It seems that 400-500watt is about as big as they typically come.

 

[Lateral Line]

Rena used to make thermostats that sat on the top edge of the glass with a clip. They had a bimetallic strip behind a flat metal plate which reacted to the tank temperature. You could switch several heaters with them. I guess they are still available. Slikstats or Constats they were called.

I have also seen many electronic heater controllers which have a small diode probe in the tank and a switching circuit in an external unit which again, can control several heaters.

Each of these solutions will of course, only switch loads up to a certain Wattage.

Yes, you can put heaters in a sump, or in a filter train. I do this, it keeps the tanks clear of clutter.

 

[Nickoli]

Thanks Lateral Line,

I have been looking around and found some similar things. Campbell Scientific makes data loggers that can set off an alarm in their software. It looks like I could have this trigger a switch to turn on, or off heaters. I haven't seen the programming but I should be able to put a few sensors in the tank, and have heaters come on or off to keep my temperature very constant. It isn't exactly plug and play, but it doesn't look to hard to make components to get this to work.

It looks like I could rig sump and inline filters to this as well, though I would also need a computer running my fish tank.... Not sure if I want to go that far yet. If I do I could constant pH readings, and probably a couple other things as well.

I'm planning to build a larger tank, so I'm going to have to run a bank of heaters. I'm not sure if I'm going to have to look for a more industrial type heater or not.

 

[Lateral Line]

If you are looking for an "out of the box" aquarium solution, google "hydor hydroset" - these are typical electronic temperature controllers. Home Depot and Big Als have them in the US. The Big Al's model is about twice the price of Home >Depot, but claims to switch 500W rather then 300W for the other.

There are many other controllers around.

If you are handy that way, the voltage drop across a Germanium diode is quite linear over the sensible range of temperatures, (Silicon diodes are also linear but the range is much smaller, Ge diodes are easier to work with). A small Op-Amp comparator and a triac or thyristor to switch the power and you have a temp controller switching any power you choose with the correct components on the power stage.