[snubbyman]

I was wondering whether to get the 7.5W or 15W Hydor Mini Heater for my 3g Pico.

My room temperature varies from 64 degrees to 72 degrees.

This is my first planted tank--I hope to eventually introduce a few RCS.

The packaging says the 7.5W unit will raise 2 gallons, 5 degrees (5 gallons, 4 degrees). I believe the 15W unit will heat 5 gallons, 5 degrees (10 gallons, 4 degrees).

I've read on this forum many think the 7.5W unit is too weak to warm even small tanks.

If using the 7.5W:
64 degrees, warms to 68-69
72 degrees, warms to 76-77

If using the 15W:
64 degrees, warms to ~70??
72 degrees, warms to ~78??

I haven't picked out flora yet. If it matters, I'm planning to use the 27W Hampton Bay "Robocop" lamp. I'm also planning to use Eco-complete.

I don't have the tank yet, otherwise I could measure the temps myself. I was hoping not to have to get another heater if the first one wasn't adequate. My understanding is that RCS like 70-80 degrees?

Great forum--I'm looking forward to getting into this hobby.

 

[FSM]

I would get the 15w. That is 5 watts per gallon, higher than you would use on a larger tank. But, a small tank has more surface area and cools off faster.

 

[snubbyman]

FSM--thanks! I got the 15W. My tank and substrate came today too, so I'll be setting everything up tomorrow! My eco-complete was frozen during transit, so hopefully it will thaw soon.

 

[GTR]

These heaters don't have any adjustment so how warm will they heat the water before they shut down? Or is it always on regardless of the temp?

As far as placement...
The box says... "Super safe even under-gravel"
The instructions say..."Be certain that the heater is not in derect contact with the following: bottom of tank, etc..."

I bought the 7.5w for a soon to be setup 3g but the more I read the more I think I'll go with a traditional heater.

SteveU

 

[snubbyman]

Hi GTR,

My understanding is that there is no adjustment--only on or off. I set up my tank today...ended up putting the 15W heater under the substrate (~1.5 inches+). I will report back with some temperature readings.

I didn't read the part about not having it touch the bottom of the tank!

 

[rengb6]

i have the 15 in my 2.5 gallon and it is perfect in winter! usually raises the tank about 5 degrees I believe.

 

[GTR]

The instructions say it should be unplugged once the weather warms, whatever that means. I'm just curious, is it on 100% of the time regardless of the temperature.

 

[StevenLeeds]

Walmart sells a reasonable Tetra heater that is autoset to 78. It's small and takes care of a 2.5 gallon with no problem. The one you're considering is an always on heater unless they have changed the design. I tried one in a 2.5 and couldn't keep the temp consistent.

 

[snubbyman]

I think it stays on no matter what the temperature is.

I'll post once I get more temp readings. Right now, it doesn't seem like it's doing much (water temp stays pretty constant no matter what room temp is: 74-75 degrees). I did bury it in the substrate, which some posts on this forum seem to indicate it will not work as well. The glass near the heater is mildly warm to the touch, but can't imagine it would have a drastic effect on the other end of the tank.

StevenLeeds, I'll have to check out that Tetra heater.