Why Do My Otocinclus Keep Dying? {How To Save Them}

Is stress causing your Otocinclus to die? Are you stressed about it? In this article, we’ll discover why Otocinclus keep dying.

Why Do My Otocinclus Keep Dying? Your Otocinclus may have arrived far too stressed to survive the crucial first month in your tank’s ecosystem. Sadly, many don’t make it. Stress, lack of appetite, water quality fluctuation or illness leads to their early death. After the first month, they should be hardier. 

Did My Otocinclus Starve To Death?

You may have noticed your Otocinclus eating, but it may have still starved to death. How is this possible?

The digestive system of Otocinclus is unique in comparison what we’re used to. Their gut bacteria could cease to function or dwindle in numbers when they are experiencing stress.

Once the gut bacteria is weakened, the food they eat won’t be processed. Otherwise, they may not wish to eat out of discomfort or inability to adjust to your tank. Try blanched vegetables or algae wafers to notice if and how much your Otocinclus is eating.

Did My Otocinclus Arrive Sick?

The Otocinclus is a tough fish to pick from the store. You can take your time and make the right choice by noticing a few factors:

  • More active
  • Suctioning the glass
  • Rounder belly
  • Has survived over a week 

The local fish store may get a new batch and you could be one of the first to choose which Otocinclus you would like to bring home. Look for the most active or ones that have already gotten to work on sucking algae off surfaces including the tank’s glass.

A rounder belly indicates they are eating well. This will help their transition to your tank to be more likely that they can survive.

Some have been through major stress when caught in the wild. Otocinclus are sometimes sedated with chemicals before they are caught and transported. This could leave them very weak. The strongest that survive in local fish shops for over a week have a better chance at being hardy.

How Do I Acclimate My Otocinclus?

Your Otocinclus will need a steady and slow process of drip acclimation. The process could take many hours if you wish to give your Otocinclus a better shot at survival.

Survival rates go up with a slow drip introduction to your tank’s water. Keep placing one drop of water at a time into the bag until they are capable of handling any changes in pH, hardness or temperature in the main tank.

Place planted matter that is dense or bushy. Add decorations and hiding spaces. Maintain the best possible water quality, but do not clean the tank’s glass too much. Your Otocinclus should help you with that.

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What Should I Do After My Otocinclus Dies?

If you see that your Otocinclus has a swollen belly, acting lethargic or hiding for days, then a slow death is possible. The moment you notice them motionless, on their side or belly up, it’s time to remove them from the tank.

Bring the Otocinclus and a sample of your tank’s water to your local fish shop if this death occurred within the first 24 hours to 1 week. See what they will do or say. A reputable shop will test your water quality and determine if they can replace the dead Otocinclus with another one.

Make sure your tank is cycled and ammonia or nitrites are reading 0ppm. The beneficial bacteria from your filter’s media should be offering support from unwanted illnesses or parasites from affecting your Otocinclus in the future.

How Can I Get My Otocinclus To Eat?

You can try multiple methods and options for your Otocinclus to eat more to prevent starvation or illness.

  • Make sure the tank is comfortable.
  • Don’t overclean the tank’s surfaces and glass.
  • Add more Otocinclus.
  • Try new vegetables.

The tank must be free of aggressive bullies. Your Otocinclus may not wish to come out of hiding and won’t eat enough. If there isn’t enough algae or plants to nibble on, your Otocinclus may give up grazing and lose interest of eating or life in general.

Try to entice their diet with more vegetables. Here’s a tip for preparing zucchini for your Otocinclus.

  • Cut it up into slices.
  • Blanche the zucchini. 
  • Remove the slices from the boiling water.
  • Let them cool.
  • Transfer them to a ziplock bag.
  • Freeze for a day. 
  • Take one out and drop it in the tank.

What Is the Lifespan Of An Otocinclus?

These common bottom-dwelling tank cleaners are often referred to at Otos. They are capable of living 3-5 years in your aquarium if you maintain clean water, optimal temperatures and plenty of space, food and vegetation.

They grow to about 1-2 inches and are easy to keep once they adjust to their new home. The first month may involve being sedated in the wild, then transferred to multiple locations before you get a chance of picking one up from the local fish shop.

Try to keep them in groups and be aware that some may not make through this stressful journey.

  • Lifespan: 3-5 years
  • Size: 1-2 inches
  • Diet: Herbivore

What Kind of Water Do Otocinclus Like?

Try to make sure the tank contains densely planted areas and hiding spaces for these shy fish to remain comfortable. The tank must have been cycled well before these Otocinclus make it home. Their ideal parameters are as follows:

  • Temperature: 72-79°F 
  • pH: 6.0-7.5
  • GH: Less Than 15°
  • KH: Less Than 10°
  • Ammonia and Nitrites: 0ppm
  • Nitrates: Less than 5ppm


We hope you have better luck with your future Otocinclus. Take your time to notice and choose the hardiest Otocinclus from the shop who are active and eating well before they adjust to your tank.

Maintain the best possible water quality for these bottom-dwelling fish and we hope you can enjoy them for the next 3-5 years.


Thanks for visiting HelpUsFish.com and we hope to see you again for another article on Otocinclus or any other marine life that interests you. 

Brian Arial

Brian Arial has kept fish for leisure and worked with fish stores for most of his life. He enjoys writing and caring for aquariums and ponds.

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