Heater too small?

Jvesche20 · Mar 5, 2019

When I got my heater 8 months ago I purchased an Eheim 250w heater. I have a 125G tank with about 35 gallons of water in the sump give or take 5 gallons. This is what my LFS sold me. In January I added a 25G frag tank that linked to my sump so around 170 gallons of water flows between the 2 tanks. assuming live rock and sand takes up some space. I never thought about this being an issue. Recently I've noticed that the water in my tank is colder than normal. None of my fish or coral are acting differently it just felt colder. I looked at my thermometer and it was reading low 70s but I thought maybe this thing is old so I went and got a new one and sure enough, it's reading about 73. My heater is set at 77. It's on and working I can feel the heat when I take it out of the sump. I have another heater that's made for 60 gallons max. I use it for my rodi water so it's not ice cold when it goes into my tank for ato and WC. The only problem is this heater is set to be at 80 and there's no adjusting it. Should I just throw it in there for now and get a larger heater tomorrow from my lfs? How do I know if my current heater is broken? Like I said I haven't noticed this before and I've had my frag tank up and running for almost 2 months no issue.

ryeguyy84 · Mar 5, 2019

I'd just pickup another 250w and a heater controller for it (or aquarium controller if you have one). It's not able to keep up with your water volume so it's probably running 24/7. Constantly running it's going to make it fail sooner and you'll have bigger issues.

Having 2 heaters is always better than 1

Scotty Buttons · Mar 5, 2019

Most heaters have a little light on them that turns on and off with the heater. I think your 250w Heater might be a little under powered. Personally I would buy a second 250 heater and run both of them. That should keep your tank temp stable also in the event of one failing you have a plan B.

K-Philly · Mar 5, 2019

Jvesche20 said:
When I got my heater 8 months ago I purchased an Eheim 250w heater. I have a 125G tank with about 35 gallons of water in the sump give or take 5 gallons. This is what my LFS sold me. In January I added a 25G frag tank that linked to my sump so around 170 gallons of water flows between the 2 tanks. assuming live rock and sand takes up some space. I never thought about this being an issue. Recently I've noticed that the water in my tank is colder than normal. None of my fish or coral are acting differently it just felt colder. I looked at my thermometer and it was reading low 70s but I thought maybe this thing is old so I went and got a new one and sure enough, it's reading about 73. My heater is set at 77. It's on and working I can feel the heat when I take it out of the sump. I have another heater that's made for 60 gallons max. I use it for my rodi water so it's not ice cold when it goes into my tank for ato and WC. The only problem is this heater is set to be at 80 and there's no adjusting it. Should I just throw it in there for now and get a larger heater tomorrow from my lfs? How do I know if my current heater is broken? Like I said I haven't noticed this before and I've had my frag tank up and running for almost 2 months no issue.

Yeah, your particular model's max threshold looks to be round 160G. Keep in mind that flowing or moving water tends to run a little cooler. If they are no visible cracks or breaks, you should be fine. Which I don't suspect there to be, because I am sure it would leach some kind of chemicals in turn killing your fish. I would just add the other heater for now, and then bump up to 300W model. Also, the top statement is a good idea as well.

sghera64 · Mar 5, 2019

Depends on the temp difference between tank and room, do you have an open top, room air recirculation, glass or acrylic tanks.

I have a 135, plus 45 gal of frag tanks plumbed In like you. I have 2x300Watts and it seems one is always on 80% of the time and both are on maybe 10-15% of the time in the winter. Temp in the room is about 69F and I have no cover over the water surface

Jvesche20 · Mar 5, 2019

ryeguyy84 said:
I'd just pickup another 250w and a heater controller for it (or aquarium controller if you have one). It's not able to keep up with your water volume so it's probably running 24/7. Constantly running it's going to make it fail sooner and you'll have bigger issues.

Having 2 heaters is always better than 1

what are the prices for the controllers for a heater? I was going to save for a Neptune apex over the summer.

Scotty Buttons said:
Most heaters have a little light on them that turns on and off with the heater. I think for 250w Heater might be a little under powered. Personally I would buy a second 250w heater and run both of them. That should keep your tank temp stable also in the event of one failing you have a plan B.

The light is on. I think I'm going to get a 2nd heater tomorrow I'm scared its going crash my tank. I've read many stories about peoples tanks crashing due to the heater failing.

mich2599 · Mar 5, 2019

Sounds like your heater may be having a hard time keeping the temp. I’d recommend buying two 250w heaters. This way you have two working instead of just one. If one fails, you have the other one working. It can also prevent the current one you have from failing in the on position and cooking all of your stuff. Look at the Jaeger heaters.

Jvesche20 · Mar 5, 2019

sghera64 said:
Depends on the temp difference between tank and room, do you have an open top, room air recirculation, glass or acrylic tanks.

I have a 135, plus 45 gal of frag tanks plumbed In like you. I have 2x300Watts and it seems one is always on 80% of the time and both are on maybe 10-15% of the time in the winter. Temp in the room is about 69F and I have no cover over the water surface

I didnt mention that but I did have glass over the top for a long time but I felt that it wasnt letting as much light through so I made my own netting and got 1/8" clear netting from brs and made screen frames and it sits on top now. It has been slightly colder outside getting to the single digits before it was staying in the 30-40s and I have the tank in the basement. The house is set to 72F

Mastiffsrule · Mar 5, 2019

I have a 180 DT and 30 gallon sump. I use a Ranco controller and titanium heater. Been in service 8 years. Never a failure. Set it years ago and never looked at it since.

https://www.supplyhouse.com/Ranco-E...MIs-zbkb_s4AIVF4vICh0huQs2EAQYASABEgIllfD_BwE

Jvesche20 · Mar 5, 2019

mich2599 said:
Sounds like your heater may be having a hard time keeping the temp. I’d recommend buying two 250w heaters. This way you have two working instead of just one. If one fails, you have the other one working. It can also prevent the current one you have from failing in the on position and cooking all of your stuff. Look at the Jaeger heaters.

I believe my 250W is an Eheim Jager heater. I lost the box but I looked up Jaeger heaters and mine came up

Jvesche20 · Mar 5, 2019

Mastiffsrule said:
I have a 180 DT and 30 gallon sump. I use a Ranco controller and titanium heater. Been in service 8 years. Never a failure. Set it years ago and never looked at it since.

https://www.supplyhouse.com/Ranco-E...MIs-zbkb_s4AIVF4vICh0huQs2EAQYASABEgIllfD_BwE

Not a bad price Ill have to check it out

K-Philly · Mar 5, 2019

sghera64 said:
Depends on the temp difference between tank and room, do you have an open top, room air recirculation, glass or acrylic tanks.

I have a 135, plus 45 gal of frag tanks plumbed In like you. I have 2x300Watts and it seems one is always on 80% of the time and both are on maybe 10-15% of the time in the winter. Temp in the room is about 69F and I have no cover over the water surface

How close are they together? One can be going off the readings of the other because it is picking up the immediate temperature of water surrounding it.

K-Philly · Mar 5, 2019

You c

Jvesche20 said:
I believe my 250W is an Eheim Jager heater. I lost the box but I looked up Jaeger heaters and mine came up

You can reference my build if need be. My heater is an Eheim Jager. Link is in my signature.

Jvesche20 · Mar 5, 2019

K-Philly said:
How close are they together? One can be going off the readings of the other because it is picking up the immediate temperature of water surrounding it.

Thats a good point. How far apart should I keep the heaters?

K-Philly · Mar 5, 2019

Jvesche20 said:
Thats a good point. How far apart should I keep the heaters?

Hm, that's tough. I would think 6" to 1' should be plenty. Or say if they are in the sump, maybe one in a chamber, and the other in another. You could probably play with it some and find a sweet spot.

Jvesche20 · Mar 5, 2019

K-Philly said:
You c

You can reference my build if need be. My heater is an Eheim Jager. Link is in my signature.

Looks like I have the same heater. I think I'm going to pick up a 2nd one tomorrow

K-Philly · Mar 5, 2019

Jvesche20 said:
Looks like I have the same heater. I think I'm going to pick up a 2nd one tomorrow

Sounds like a plan, I've always been into Eheim products. Been around for a long time and seem to be pretty reliable.

sghera64 · Mar 5, 2019

K-Philly said:
How close are they together? One can be going off the readings of the other because it is picking up the immediate temperature of water surrounding it.

The temp probes for each heater is separate and away from the two heaters and down stream. I calibrated the probes and controllers (JBL and InkBird) while in the sump with a traceable handheld.

The two heaters are parallel and next to each other, but that should be inconsequential.

sghera64 · Mar 5, 2019

Jvesche20 said:
Thats a good point. How far apart should I keep the heaters?

I recommend a heater that does not have an integrated thermal probe. Then you have flexibility on where to place the sensor (up stream, down stream, parallel to).

Often it is the thermistor that fails. External ones can be replaced for a fraction of the cost of a whole new heater. And if you are handy with a soldiering iron, you can replace a bad one for less than a buck. Fully integrated heaters have to be completely replaced if any component fails.

K-Philly · Mar 6, 2019

sghera64 said:
The temp probes for each heater is separate and away from the two heaters and down stream. I calibrated the probes and controllers (JBL and InkBird) while in the sump with a traceable handheld.

The two heaters are parallel and next to each other, but that should be inconsequential.

Sometimes I am not so good with visualization in my head. I have been getting better with that! However, I just want to regurgitate some things to you to be sure I am on the same page.

The heaters are connected to a base outlet, which is how they are controlled via a controller. The controller uses the probes, and kicks the heaters on and off accordingly, much like how an Apex would work? So, if these heaters do have internal thermostats, they are more than likely being overridden? If I could get a picture it would help me understand the placement better.