What's the best temperature for pleco catfish?
Because there are many pleco species that have different preferences in terms of water temperature, there isn’t one single answer for this. However, there is a range in which most pleco species can live.
The best water temperature for most pleco types is between 72°F and 76°F (22-26°C). Because they originate from the Amazon rainforest, they need warm temperatures Certain species like zebra plecos prefer higher temperatures 82°F between 88°F (28-31°C).
Pleco species and their desired temperature
Bristlenose pleco (Ancistrus cf. cirrhosus)
Common pleco (Hypostomus punctatus)
Clown pleco (Panaqolus maccus)
Flash pleco (Panaqolus albivermis)
Zebra pleco (Hypancsitrus zebra)
Hypancistrus sp. (L333))
Queen Arabesque Pleco (Hypancistrus sp. (L260))
Snowball pleco (Hypancistrus inspector)
Leopard frog pleco (Peckoltia compta)
Candy Striped Pleco (Peckoltia vittata)
Peppermint pleco (Paracistrus nudiventris)
Golden Nugget Pleco( Baryancistrus xanthellus)
Sailfin Pleco (Pterygoplichthys pardalis)
Rubbernose pleco (Chaetostoma sp.)
Vampire pleco, Galaxy pleco (Leporacanthicus galaxias)
Royal pleco (Panaque nigrolineatus)
Sources: PlanetCatfish.com, Seriouslyfish.com, Fishbase.se.
Do plecos need a heater?
It’s one of the questions that’s asked the most in terms of setting up a tank for pleco catfish. And the answer might surprise you.
Plecos need a heater in their tank. They originate from the Amazon tropics, so warm water is necessary to keep them happy and healthy. If you live in a warm area where it’s constantly between 72°F and 80°F, a heater isn’t necessary. The preferred temperature varies per species, as some species are more sensitive and need higher temperatures.
To play devil’s advocate for a second, in some cases you don’t need a heater to keep pleco catfish. Especially in the summer and if you live in an area which stays above 72°F, most pleco species tend to do fine without a heater. Please look at the table above to see whether the species you want to keep can live in these temperatures.
What happens if the water is too cold?
Most commonly available pleco species are rather hardy. They can withstand lower temperatures for long periods of time, and often do well in lower than often claimed temperaturs.
However, when the temperature gets too cold, plecos will become sick and eventually die. Here are a few symptoms that occur if your water is too cold:
- Slow, inactive fish due to lower metabolism
- Lower immunity, causing the fish to fall sick more easily
- Lower reactivity to food/movements
This is why I recommend keeping pleco catfish at a minimum of 70°F (achieved with or without a heater). At this temperature, most species do fine, especially because they are most likely used to that in the breeding facility/store.
Note: if you notice your tank is too cold, it’s extremely important to slowly and gradually higher the temperature of the water. Otherwise, your fish will die of temperature shock!
Can plecos be kept in cold water?
Plecos can’t be kept in cold water, or in any temperatures below 72°F, for a long period of time. Some plecos can do well at lower temperatures for some time, but in order for these fish to thrive, temperatures should not drop below72°F.
What happens if the water is too warm?
Unfortunately, this is a problem which regularly occurs with fish tanks. Heaters can break or a heatwave can hit you. If this is the case, it’s necessary to cool down the fish tank as soon as possible, otherwise the following things will happen:
- Rapid gill movement
- Faster swimming and being more reactive
- Gulping at the surface
This is mostly caused by a lack of oxygen in the fish tank. However, useful bacteria will die causing a spike in nitrites, nitrates and ammonia. All of which can be deadly.
Thus, the fish will not be able to take in enough oxygen causing the above reactions.
What to do if the water is too warm?
First, try to find the cause of this problem. Make sure to check whether your heater isn’t broken and pull it out of the tank, since a broken heater might cause an overheated tank ( I’ve had to deal with boiled shrimp once, not very nice when returning from a trip).
But this can also be the case of just high temperatures outside or in your house, so then you’ll need to find a solution.
Here are some things you can do to cool down water:
- Use a fan to blow on the water
- Put a small amount of ice blocks in the tank (be very cautious, that the temperature gradually drops)
- Add colder water to the tank (again, be very cautious, so that the temperature gradually drops).
How to minimize temperature fluctuations
Many pleco species prefer a temperature of between 72 and 76°F. There are species however like Hypancistrus zebra that need temperatures upwards of 79°F.
Some pleco types like bristlenose plecos are hardy fish that can live in a variety of different conditions and temperatures. In some cases, you can even not use a heater without much trouble. There are however a lot of pleco species that are more sensive such as Peckoltia or Hypancistrus species.
If water is too cold your fish’s metabolism will drop, causing lower activity levels and lower immunity.
Water that’s too warm on the other hand causes an oxygen crash, causing fish to gasp at the surface and many beneficial bacteria to die. You can do a couple of things:
- Set up a fan to blow at the surface, and open the lid.
- Take out the heater and check whether it’s broken.
- Add colder water / ice (be very cautious to gradually drop the temperature of the water)