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Heater for 2.5 gallon tank

27281 Views 28 Replies 12 Participants Last post by  natemcnutty
Hey guys, so I have a little 2.5 gallon tank I set up just over a week ago for some Red Cherry shrimp. After looking at the temperature of the water for several days, I think the tank will need a heater, as it stays around 70. As far as I know, this is a little on the chilly side for the shrimp so I would like to get a heater. However, at the Petco I work at, I believe the smallest heater we carry is a 50 W. I'm no expert, but it seems like this would be too much power for a 2.5 gallon tank. Any suggestions on what a good heater would be? Thank you
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I would think a 50w would be fine, assuming you get a high quality heater that turns off when it reaches its desired temp. Otherwise, there are 25w heaters out there. In either case, the Cobalt Neo-Therm line of heaters is recommended a lot (pricier compared to glass heaters, but no worry of breaking).

No matter what option you go with, a temperature controller is also something to look into. Can't speak for any particular brand myself though.
Decided to research this heater it's $109.60!!! with tax here in Canada for 150w. I just got an eheim Jager 2 weeks ago from petsmart during their 25% off sale for under 30 taxed and it's the most accurate heater I own.
With that small tank and 50 watt, I would not touch it! A ten gallon can go from okay to cooked and dead in less than 6 hours, so I might guess the time on 2.5 as maybe around 2-3 hours?
So when I was faced with wanting no heater showing as well as a much smaller heater, I went DIY. This is a link to what I did at the time but it is not much help now as all the pictures are lost due to various computer and photo sharing changes.
http://www.plantedtank.net/forums/20-diy/927097-no-equipment-seen-challenge-3.html
Basic idea of the project is that I built a box for the tank to set on and hide lights at the base, rather than have a heater in the tank. Small needs little heat so just a set of light bulbs or other simple heat might fit for your use? Tied to one of the simple $10-12 temperature controllers, the set can be very cheap --if the DIY is of interest.
One of the turtle heating pads, tied to a controller might be an option, as well.
I use Hydor 25W Submersible Aquarium Heater for my 3 g, also placed it in my 2.5 g for a week. It's adjustable so you don't have to worry about turning it off like other cheaper heaters. You just have to adjust the heater to lower value you want it at because it's a smaller tank. Like if you want it at 80 degrees then place it at like 75 degrees or something around that.

https://www.amazon.ca/gp/product/B0006JLPG8/ref=oh_aui_detailpage_o02_s00?ie=UTF8&psc=1
Hey guys, so I have a little 2.5 gallon tank I set up just over a week ago for some Red Cherry shrimp. After looking at the temperature of the water for several days, I think the tank will need a heater, as it stays around 70. As far as I know, this is a little on the chilly side for the shrimp so I would like to get a heater. However, at the Petco I work at, I believe the smallest heater we carry is a 50 W. I'm no expert, but it seems like this would be too much power for a 2.5 gallon tank. Any suggestions on what a good heater would be? Thank you
Question is being in Florida do you even need a heater for shrimps?

I am at NJ and none of my shrimp tanks have heater including a 2.5gallon and 1gallon. Room temperature stays above 63F.
Question is being in Florida do you even need a heater for shrimps?

I am at NJ and none of my shrimp tanks have heater including a 2.5gallon and 1gallon. Room temperature stays above 63F.
well the water ends up staying around 70, but is that acceptable for the shrimp? seems a little chilly and on those little aquarium thermometers its just below that little green area.
I have a small 2.5 gallon betta tank that he is chilling in while his 20 gallon gets totally set up. I have this submersible heater that raises the temperature about 4-5 degrees above room temperature and works pretty well. It actually shuts itself off and has not cooked my betta.

I'm not sure what stores in your area would have it, but I found it on amazon for you. I bought it at my local pet store. Hope this helps :)
well the water ends up staying around 70, but is that acceptable for the shrimp? seems a little chilly and on those little aquarium thermometers its just below that little green area.
Yes its perfectly ok. Shrimps prefer cold water.
Unless you are looking to increase the population there is no reason to raise the water temp. The ideal temperature is 72F.

And never trust any heaters, how costly it is, it doesn't matter.
Funny this is asked. I have the heater referenced by @sorepatrol68 and walked in to work this morning to find my Betta had past on.

Long story short, I grabbed a thermometer from home and at 2 pm the water was 92 degrees and the heater had not turned off all day.

I'm not necessarily knocking the heater itself because I know this can happen with any piece of equipment, but that 25 watt heater raised the temperature from the 78 it was set at well over ten degrees over the weekend.

I would either make sure you need it or consider investing in something like a controller.

I'm also in Florida and the office temp in the office is averaging 76. In retrospect, I should have left well enough alone and not added another possible failure point.

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Funny this is asked. I have the heater referenced by @sorepatrol68 and walked in to work this morning to find my Betta had past on.

Long story short, I grabbed a thermometer from home and at 2 pm the water was 92 degrees and the heater had not turned off all day.

I'm not necessarily knocking the heater itself because I know this can happen with any piece of equipment, but that 25 watt heater raised the temperature from the 78 it was set at well over ten degrees over the weekend.

I would either make sure you need it or consider investing in something like a controller.

I'm also in Florida and the office temp in the office is averaging 76. In retrospect, I should have left well enough alone and not added another possible failure point.

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Omg.... I'm sorry for your loss :(

So far my sister and I haven't had any problems with this heater. She has it in a 5g and I have it in a 3g. We also live in Vancouver, Canada where room temp is about 20 degrees Celsius and my room is about 25 when I turn on my heat. Maybe your existing room temp is enough? Or the heater is faulty...

How big is your tank btw? @psych

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Omg.... I'm sorry for your loss :(

So far my sister and I haven't had any problems with this heater. She has it in a 5g and I have it in a 3g. We also live in Vancouver, Canada where room temp is about 20 degrees Celsius and my room is about 25 when I turn on my heat. Maybe your existing room temp is enough? Or the heater is faulty...

How big is your tank btw? @psych

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My tank is small, 2.5 gallons. I initially bought the heater because the office temp hovered around 76 and I wanted the tank just a bit warmer. It worked for a while with no issues and I found it did keep a steady temp when it was working.

The heater was definitely faulty, which is unfortunate. If I decide to get another Betta I'll probably just let it go at room temp. No sense adding a piece of equipment to fail if it's not needed.


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My tank is small, 2.5 gallons. I initially bought the heater because the office temp hovered around 76 and I wanted the tank just a bit warmer. It worked for a while with no issues and I found it did keep a steady temp when it was working.

The heater was definitely faulty, which is unfortunate. If I decide to get another Betta I'll probably just let it go at room temp. No sense adding a piece of equipment to fail if it's not needed.


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If you do decide to get another betta, just make sure to monitor the temp of the water. Most of the time temp of the room isn't the same as the water. But since you live in Florida I'm sure it's not that bad. I know for a fact if I don't have a heater my water is about 70-72 degrees which is way too cold. You should maybe try and complain to the company... for murder. LOL
I'm guilty of not having a thermometer in the tank, but I will from now on. Unfortunately it probably wouldn't have saved Fred since this happened over the weekend.

I know he has been alright in the past without a heater so I think I'll probably go that route. Even if he's a little cold at least he won't boil. Poor guy.

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The point that newer folks may miss is that the heaters are one of the most dangerous items in our tanks. We do all kinds of things to avoid chlorine, ammonia, nitrates and ignore the simple heater as it just sets there in the corner. That is like walking past a ticking time bomb!
Electro-mechanical things fail, right? Some last longer than others but heaters are not one that are known in our hobby as a good piece of equipment .
So the question is not so much if they will fail but how to keep it from doing us in if/when it happens.
I won't even say it happens often as I have only had it happen three times in nearly fifty years.
But the really big thing that sticks in my mind is that it can totally wipe out the entire tank and that is just really a downer that I do not want to happen again.
Total up what you have spent on the tank (time, effort, and money) and then ask how you will feel if it is all dead tomorrow.
I've purchased and returned those 25W (fixed and adjustable) heaters sold in the pet stores. They just felt cheap, even though they technically worked. All heaters can fail, but I feel more comfortable with Aqueon Pro and Eheim Jager.

I'm using an Aqueon Pro 50W in a 2.5 gallon right now for newborn fry, and also in a 10G. I use the 150W in a 40g. The glass is coated in heavy black plastic so it won't break, and it blends into the tank better than the others. I have Eheim Jager for larger tanks, but never tried them smaller because they run slightly longer in length. Their calibration is nice.
The best price seems to be Amazon, often 1/2 of the stores.

I keep my Bettas at 76F although they can handle low 80's. I kept one unheated in the winter and the tank (bowl) was as cold as ice water when returning from a trip - heat was off in the house. That was before I knew tanks were heated (he was a gift and my only fish). I share this because other tropical fish wouldn't survive these temps, and Bettsa are quite hardy.
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I've purchased and returned those 25W (fixed and adjustable) heaters sold in the pet stores. They just felt cheap, even though they technically worked. All heaters can fail, but I feel more comfortable with Aqueon Pro and Eheim Jager.

I'm using an Aqueon Pro 50W in a 2.5 gallon right now for newborn fry, and also in a 10G. I use the 150W in a 40g. The glass is coated in heavy black plastic so it won't break, and it blends into the tank better than the others. I have Eheim Jager for larger tanks, but never tried them smaller because they run slightly longer in length. Their calibration is nice.
The best price seems to be Amazon, often 1/2 of the stores.

I keep my Bettas at 76F although they can handle low 80's. I kept one unheated in the winter and the tank (bowl) was as cold as ice water when returning from a trip - heat was off in the house. That was before I knew tanks were heated (he was a gift and my only fish). I share this because other tropical fish wouldn't survive these temps, and Bettsa are quite hardy.
Thanks for saying this.. if I try again I'm going to skip the heater at first and hope the office stays warm enough. If I do need one though, you can bet I'll monitor it daily.

As an aside, and apologies for derailing if I am, can someone help me understand why controllers are so often recommended? I assume that the controller also has a thermometer that would allow it to past voltage to the heater. If the heater goes bad and stays "stuck on" and the controller then goes bad, wouldn't one end up with the same mess? Or do controllers go bad less often?
Thanks for saying this.. if I try again I'm going to skip the heater at first and hope the office stays warm enough. If I do need one though, you can bet I'll monitor it daily.

As an aside, and apologies for derailing if I am, can someone help me understand why controllers are so often recommended? I assume that the controller also has a thermometer that would allow it to past voltage to the heater. If the heater goes bad and stays "stuck on" and the controller then goes bad, wouldn't one end up with the same mess? Or do controllers go bad less often?
Somewhat true in the case of preset heaters. Especially if there is no indicator showing when its operational.

If you have adjustable heaters, the odds of both getting damaged are less. The more redundancy the more peace of mind.
Yes its perfectly ok. Shrimps prefer cold water.
Unless you are looking to increase the population there is no reason to raise the water temp. The ideal temperature is 72F.

And never trust any heaters, how costly it is, it doesn't matter.
Oh so I should be okay? I would like them to breed though if I could get away with it. I may get one of the adjustable or "maintains temperature" heaters for the tank, but if they can breed in the cooler water, no need.

All this talk of heater being ticking time bombs is scary! I have some good ones though, but paranoia sets in quick!
Thanks for saying this.. if I try again I'm going to skip the heater at first and hope the office stays warm enough. If I do need one though, you can bet I'll monitor it daily.

As an aside, and apologies for derailing if I am, can someone help me understand why controllers are so often recommended? I assume that the controller also has a thermometer that would allow it to past voltage to the heater. If the heater goes bad and stays "stuck on" and the controller then goes bad, wouldn't one end up with the same mess? Or do controllers go bad less often?

I would think the odds of both going "bad" at the same time are very high against . I keep my heaters set just above what temp I want so if the controller did stick on the temp wouldn't rise too much .
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