Types of submersible aquarium heaters and instructions - with forum

Our livestock depend on us to give them the correct temperatures to live in, they are cold blooded so the only way that they can get any heat into their bodies is through the tank water.

In the early days of fish keeping immersible heaters were available, these hung on the back of the tank with the heating probe in the water, and the thermostat was a separate unit that was kept over the tank in the dry. For this reason they are commonly known as hang on heaters, but nowadays these have been replaced with a new range of heating equipment, the fully submersible heater.

The whole unit is placed in the water, the heating element and thermostat are built into the unit, and this means that the only piece out of the water is the wire for connection to the mains.

There are several manufacturers producing this piece of equipment and we shall look at some of these further on in this article.

The temperature levels are set by means of a knob on top of the heater, the higher quality models will also have a scale on the side, and this will then tell the user the temperature that the heater has been set to.

All of the heaters are sold by the wattage that they run at, the larger the aquarium, the higher the wattage required to heat the water, in some cases with the larger tanks it is quite common to have a heater placed at both ends to ensure that a constant temperature is maintained throughout.

Most submersibles are enclosed in a glass tube, because of this they will break if knocked, some models claim to be shatter proof but I would not like to put them to the test. If you do break the glass never try to repair it, always invest in a new unit, if your repair fails you will be mixing electricity with water, definitely not a good idea.

How do I know which heater to buy:-

Always go for the best quality you can afford, check the extra features that the heater is advertised as giving you. The wattage required will depend on the size of your tank, below is a rough guide as to which you will need, if you are unsure always ask for advise.

If running a larger tank then a combination of the two will ensure a constant temperature

Placement of the heater (s):-

Bit of an obvious statement but believe me, if have seen some very strange placement of heaters in some tanks. Always try to place your heater near flowing water, next to the outlet from your filter is ideal, this will ensure the heat will be dispersed throughout the tank.

I prefer to have my heaters mounted at a 45 deg angle on the back of the tank as I think the heat radiation is more efficient, having said that I know a few fish keepers that place them in a horizontal position for the aesthetics of the tank.

• Always purchase a quality thermometer to monitor the heater.
• If possible keep a spare heater to one side in case of emergencies.
• In new set ups, run the heater for 24 hours to make sure that it is set to the correct temperatures, if it is set to a certain temperature on the heater scale it may vary in the water, in this case a bit of fine adjustment up or down will be required.
• Never remove the heater from the water if switched on, it will blow the glass and could cause injury to you.
• If you need to remove the heater for tank maintenance, switch it off 10 minutes prior to removal, this will allow the heater to cool down.

As mentioned previously there are a lot of well known brands on the market, they all do the job they are supposed to, but some have better qualities than others ,hopefully this short guide will give you some ideas as to which types to choose, but please bear in mind, this is my personal opinion, other people may have different preferences.

Jewel Heaters:-

These heaters are supplied with their tank set ups and range from 50 watts to 300 watts. They are available to buy separately for approx. 20 pounds (40 dollars) depending on where you buy.

The glass casing with these is quite strong but what you see is what you get, no fancy extras but they are reliable. The only drawback I have found with these is that they do not come with a scale for temperature setting. The adjustment knob is on the top and the only indication for the adjustment is a plus and minus sign, this means that obtaining the correct setting is very much trial and error. Once set though, they will run with no problems.

Visitherm heaters:-

This is a very well constructed heater, it comes as standard with a temperature dial on top, this is definitely a bonus when re-adjusting the settings while the heater is situated in the tank. There is a large scale that can be read easily on the side of the glass, this can confirm which temperature has been selected. Visitherm is produced by marineland who also produce the stealth range of heaters. The great benefit of the stealth range is the plastic casing that is used rather than glass. This makes it virtually unbreakable but all the visible scales are also included. Both ranges are available from 25 watts up to 300 watts and price wise there is not a lot of difference between the two. The 25 watt models sells for approx. 8 pounds (16 dollars), the 300 watt model sells at approx. 10 pounds (20 dollars).

I think these are good value for money.

Rena heaters:-

This has to be my favorite brand of heaters. The Rena cal series was well ahead of some of its competitors when it first arrived on the scene. The units are triple sealed for extra protection, plus the glass is 2mm thick for extra strength. Setting the temp is easy with a well graduated control knob and visible scale. The main benefit with these is the fact that the heating coil heats the glass case directly so that the heat is much quicker entering the water. Other models heat the air encased in the glass, making them less efficient. It incorporates a solid silver thermostat contact that can react to changes in the water temperature very quickly. Prices range from 10 pounds (20 dollars) for a 50 watt version, up to 15 pounds (30 dollars) for the 200 watt version.

Rena also went one step further with their designs and produced the Rena smart heaters. These heaters are supplied in a stylish but strong plastic casing. They have a built in electronic sensor which will alert the aquarist if the temp drifts 3 degrees out of range above or below. This is done by means of a warning light that will flash repeatedly. The other great advantage of this model is that it will automatically switch off when it is not totally submerged in water.

All of these extras do add money to the price, but well worth it in my opinion.

50 watt models sell for 25 pounds (50 dollars), 300 watt models sell for 30 pounds (60 dollars).

There are many more heaters on the market but that was a list of my three favorites.