Heater Size

[MMAX]

What size of heater would I need for a 100gal tank/ 50gal sump? 1 or 2? How many watts?

[mike31154]

Two smaller is recommended over a single large. That way you have a backup in case one stops working or gets stuck on. A large heater stuck in the ON position can cook your livestock. Many folks also use a temperature controller and/or aquarium controller to automate heater control and minimize problems.

I'd say two 150s or two 200s should do it for you, depending on where you're room temperature is at most of the time.

[MMAX]

Thanks...I was thinking I'd probably need at least 400W. I'll get 2 200W heaters.

[sphelps]

I run a single 300W on my 100gal + sump.

If you go with two smaller heaters you should run them on a single controller so they both turn on at the same time, otherwise syncing them will be difficult. If they are not synced only one will be primarily active and if the wattage is too low the duty cycle will be longer which could cause premature failure and less stable temperatures overnight. For this reason if you wish to use two heaters independently be sure to use two larger models, I would suggest two 300W units over 200W units unless a controller is used. Or use a primary unit at 300W and a smaller unit for backup.

[The Grizz]

I have 2 200w in my sump but have an issue with temp variations from 78 - 81. Is this a big deal? What can I co to keep a steady temp?

Don't mean to jack the thread MMAX this might just help us both.

[sphelps]

Originally Posted by The Grizz

I have 2 200w in my sump but have an issue with temp variations from 78 - 81. Is this a big deal? What can I co to keep a steady temp?

Don't mean to jack the thread MMAX this might just help us both.

Provided the variation in temperature is a result from the heaters (tank temp falls below set point) you should either combine both heaters with a single controller or upgrade to a single larger unit. I see little point in using two small units instead of the correct size, if you want a backup heater then you need two units, each large enough to handle the tank volume or a large primary and a smaller backup. But really unless you pay little attention to your tank you'll notice a heater failure before livestock is overly effected (especially large volume systems), quality and correct sizing is your best protection.

[corrosionjerry]

Originally Posted by sphelps

Provided the variation in temperature is a result from the heaters (tank temp falls below set point) you should either combine both heaters with a single controller or upgrade to a single larger unit. I see little point in using two small units instead of the correct size, if you want a backup heater then you need two units, each large enough to handle the tank volume or a large primary and a smaller backup. But really unless you pay little attention to your tank you'll notice a heater failure before livestock is overly effected (especially large volume systems), quality and correct sizing is your best protection.

So the combined size of the mother tank and sump size dictate the size of the heater.... so where in the sump should the heater be put ( input water or in the Refugium ) ?

[Bloodasp]

Refuge normally have a very low flow so not really ideal, it will heat up the surrounding water but it won't spread out too much. If you put it somewhere where there's too much flow it won't work efficiently either. Find somewhere in your sump where there is a good flow of water. That's my opinion anyway.