Problem with Fluval M series heater or is it something else ?

Idech · Nov 8, 2021

I have a heating problem in the tank and I’ve been trouble shooting it for 2-3 days now and finally decided it wasn’t the inkbird and that I needed to buy a new heater.

I wanted it today so I bought an overpriced Fluval M300 (300 watts) at 91$. I figured the 16$ extra was worth being able to sleep without worrying about the tank.

Well, let’s just say I hate this heater ! The knob to adjust temperature is very hard to dial when you’re standing across the tank. The light when it comes on is a pale blue/green, barely noticeable. And the light keeps shutting off after a few seconds. So I don’t know if the heater is working and it’s just the light doing weird stuff or if it’s not working. I know the inkbird is doing it’s job because I’ve thorougly tested it and the other heater, an Eheim jager, is staying on perfectly.

I’ve set the dial to 29-30C and the Inkbird is set to 25,3C so it should turn on and stay on.

Does anyone have one with the same problem ? I figure it’s not going to last long if it turns on and off 20-30 times when the inkbird turns it on.

I’ll call the store tomorrow and bring it back. I’m afraid that’s the last one they had so I hope they accept to give me my money back so I can get another somewhere else.

Oh, I just had a thought…. Can having 1x200 watts heater and 1x300 watts heater be causing problems with the Inkbird ? I hadn’t thought of that !

blaxsun · Nov 8, 2021

The Inkbird isn't really designed to work with controlled heaters, so I suspect this may be part of the issue.

Idech · Nov 8, 2021

blaxsun said:
The Inkbird isn't really designed to work with controlled heaters, so I suspect this may be part of the issue.

What do you mean, controlled heaters ? It’s just a regular heater with a control knob, just like the Eheim jager that is working fine.

This one just works for 1 minute, then turns off again. It makes no sense at all. I’ve never ever seen a heater like that.

blaxsun · Nov 8, 2021

The Inkbird is designed to work with non-controlled heating elements.

Idech · Nov 8, 2021

blaxsun said:
The Inkbird is designed to work with non-controlled heating elements.

Yes, I understand that part, but I don’t know what a non-controlled element is. Can you explain and give me examples ?

blaxsun · Nov 9, 2021

Just an inert titanium rod with a heating element jammed into it. It has no ability to turn on or off or self-regulate.

Idech · Nov 9, 2021

blaxsun said:
Just an inert titanium rod with a heating element jammed into it. It has no ability to turn on or off or self-regulate.

Everyone uses them with regular heaters, set to 1 degree above the set temperature on the Inkbird. This is so the Inkbird controls the heaters and they never have to come on or off by themselves.

That’s what they’re made for and sold as, at least the aquarium version. I don’t think that’s my problem. I’ve been using this Inkbird like that for 1 1/2 year and it was fine. I had a 15 year old heater that stopped working, I believe, and bought another one that’s malfunctioning. Thus this post.

LiveFreeAndReef · Nov 9, 2021

Use the inkbird as an emergency shut-off if the heater sticks on, and let the heater do its thing

Idech · Nov 9, 2021

LiveFreeAndReef said:
Use the inkbird as an emergency shut-off if the heater sticks on, and let the heater do its thing

I‘ve thought of using the heater stand alone but the problem is the opposite : it doesn’t stay on. I will be testing it in a bucket of water today.

And will bring it back if it doesn’t work.

Idech · Nov 9, 2021

I am testing the heater stand alone in a bucket of water with an airstone. The same thing is happening : the heater comes on for about 60 secondes, shuts off for 1-2 minute and turns on again. This is an endless cycle.

I’ve written to Fluval as they don’t answer the phone.

jassermd · Nov 9, 2021

Sounds to me like you have a bad heater...
Like you, I have my Eheims set at 80 and my Apex controls the temp at 77-78. Heater knob is set as a failsafe in the rare case the Apex doesn't turn it off. Had it set up like this in 2 tanks without any issues for over a year.

LiveFreeAndReef · Nov 9, 2021

Idech said:
I am testing the heater stand alone in a bucket of water with an airstone. The same thing is happening : the heater comes on for about 60 secondes, shuts off for 1-2 minute and turns on again. This is an endless cycle.

I’ve written to Fluval as they don’t answer the phone.

Does it not reach the desired temperature?

Idech · Nov 9, 2021

LiveFreeAndReef said:
Does it not reach the desired temperature?

It looks like it’s going to get there but not yet. Even if it does, I’m worried that with the constant turning on and off, this heater won’t last long. Unless Fluval tells me that’s how they designed it.

Right now I have only one 200 watt heater plugged into the Inkbird in the tank and it’s keeping the temperature stable. At night, when the temp drops to 18C, this won’t be enough and that’s when the low alarms wake me up. I need the second heater to do it’s job, which the Fluval M300 isn’t doing.

LiveFreeAndReef · Nov 9, 2021

Idech said:
It looks like it’s going to get there but not yet. Even if it does, I’m worried that with the constant turning on and off, this heater won’t last long. Unless Fluval tells me that’s how they designed it.

Right now I have only one 200 watt heater plugged into the Inkbird in the tank and it’s keeping the temperature stable. At night, when the temp drops to 18C, this won’t be enough and that’s when the low alarms wake me up. I need the second heater to do it’s job, which the Fluval M300 isn’t doing.

If you're able to return it, the Fluval E series heaters are awesome. Not sure what the price would be though, I saw that you had paid about $90 for the M series but a 300w E series is less than $60 (here in the states anyway..)

Idech · Nov 9, 2021

LiveFreeAndReef said:
If you're able to return it, the Fluval E series heaters are awesome. Not sure what the price would be though, I saw that you had paid about $90 for the M series but a 300w E series is less than $60 (here in the states anyway..)

Yeah, this local store is overpriced. The same Fluval M300 was 55$ CAD everywhere else. Let’s hope they give me my money back so I can buy online.

I don’t have a sump; is the E serie heater bulky ? I’m afraid it would look big and ugly in the tank…

LiveFreeAndReef · Nov 9, 2021

Idech said:
Yeah, this local store is overpriced. The same Fluval M300 was 55$ CAD everywhere else. Let’s hope they give me my money back so I can buy online.

I don’t have a sump; is the E serie heater bulky ? I’m afraid it would look big and ugly in the tank…

Eh it's bulky-ish? lol Im not sure how it'd compare to the M series in size. It's got a built in fish guard, but it does have a nice clean look to it. I found some measurements for it:

Idech · Nov 9, 2021

The heater did bring the temperature to the desired level in the bucket and kept it stable, even though it’s only on for 60 seconds at a time. The bucket holds about 1,5 to 2 gallons of water.

I’m now testing in the tank and whereas my 200 watt Eheim jager takes 30-40 minutes to bring the temperature up 0,3 degrees celcius, this 300 watt thermometer has only brought the temperature up 0,1 celcius in 42 minutes.

I replaced the Fluval with my old Eheim jager, to test it also. It took 3 minutes to increase temperature by 0,3 Celcius. Now I know my old heater is fine. 400 watts total is just not enough to keep the temperature of the tank within 0,5 celcius of the set temperature, at night when it is colder. I was right to want to replace a 200 watts heater with a 300 watt heater. Let’s find one that works.

The Fluval is definitely going back to the store tomorrow.

Idech · Nov 10, 2021

I brought it back to the store and I was fortunate enough that they didn’t have another one so they gave me my money back, lol !

LiveFreeAndReef · Nov 10, 2021

Idech said:
I brought it back to the store and I was fortunate enough that they didn’t have another one so they gave me my money back, lol !

Nice! My LFS would just laugh at me and refuse to take anything back that isn't in the original packaging. (like you're supposed to know something doesn't work without plugging it in..)

Idech · Nov 10, 2021

LiveFreeAndReef said:
Nice! My LFS would just laugh at me and refuse to take anything back that isn't in the original packaging. (like you're supposed to know something doesn't work without plugging it in..)

I have to admit I am obsessed with keeping original packages intact and when I return something, most of the time you can’t even tell it was open.

My basement is full of boxes, in case I move or have to return something. I’m kind of OCD, lol !