Can Guppies and Siamese Algae Eaters Live Together?

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As the title suggests, this article is about setting up the ideal community tank. Now, before we get to the meat of it, let’s discuss the potatoes first. Most novice aquarists have difficulties deciding which fish species to prioritize over the others. When it comes to aquarium species, you have hundreds of species with thousands of subspecies to choose from.

This can lead to confusion and even contribute to choice paralysis, where people simply don’t know which fish to pair with which. Here’s a good advice to bring some order in all the chaos. Choose fish species that complement each other and have different roles in the ecosystem.

This brings us to today’s topic – guppies and Siamese algae eaters. Can these 2 species get along with each other, and what should you know about them?

Let’s dive right into it!

Do Guppies and Siamese Algae Eaters Get Along?

In theory, yes, they should get along just fine, provided you ensure optimal living conditions. You can only achieve this by assessing each species and understanding what makes them different in the first place.

Here are the essential differences between the two fish species:

  • Different size – Guppies can only reach around 2.5 inches in length, and that’s the females. Males are typically shorter, around 1.5 inches. This is petty compared to the Siamese’s 6 inches as a full-grown fish. In a different scenario, this size difference can create problems, as larger fish quickly get into the habit of bullying the smaller ones. This doesn’t typically happen with Siamese algae eaters and guppies because of the next point.
  • Different habitable areas – Guppies prefer mid to high swimming areas, sometimes reaching the water’s surface in their quest for food or fun. On the other hand, Siamese algae eaters prefer the lower areas of the tank. They will remain close to the substrate and lurk around algae-rich zones until the area is clean. They will prioritize the substrate area due to the food opportunities it offers. This will minimize the interactions between them and guppies, especially if the tank is heavily planted, providing the latter with plenty of hiding spots.
  • Different behaviors – Guppies tend to be generally calmer and low energy. They aren’t apathetic, but they aren’t too explosive either. Siamese algae eaters, however, rather fall into the latter category. They display a more energetic behavior, which can rattle calmer fish species like guppies. To prevent this problem, provide guppies with a multitude of hiding spots to retreat to when stressed or tired.

Other than that, there’s no reason why guppies and Siamese algae eaters wouldn’t get along with each other. So long as you find ways to accommodate both species, they should live in harmony with each other long-term.

Keeping Guppies with Siamese Algae Eaters

But enough with the generalized talk. Let’s dive into the specifics and have a look at the parameters that need tweaking to accommodate these fish in the same environment.

– Tank Size

Generally speaking, guppies require around 2 gallons of water per fish. This can, obviously, vary depending on the fish’s size and gender. Males, for instance, may require more space due to their territorial behavior, which is that much more visible the more males share the same space.

Aside from the fish’s size and territorial tendencies, you should also consider the fish’s social behavior. Guppies, for instance, need to live in shoals, and they perform the best in groups of at least 6 individuals. That would be 2 males and 4 females, although I would keep 3 females for every male to minimize mating-related male aggression.

Knowing this, a 15-gallon tank is perfect for a group of 6 guppies.

On the other hand, Siamese algae eaters are way larger than guppies. At 6 inches in length, 1 Siamese fish requires around 20 gallons of water. You can then add 10 gallons for each Siamese you add to the equation. The difference is that, although this species also abide by a shoaling system and prefer the company of their own, they don’t require it. You can only keep one fish or a pair with no problems.

Combining the 2 species requires some planning, as you need to consider the tank’s size depending on how many specimens you’re expected to keep.

– Water Temperature

Guppies and Siamese algae eaters have adapted to the same water temperatures. You can set up the environment to temperatures between 72 to 80 F and they will both be comfortable. Just make sure the water temperature doesn’t fluctuate too much or too often.

I suggest installing a heater, especially if the tank’s room doesn’t remain stable in terms of temperature. Guppies can handle some temperature changes, but frequent fluctuations may stress them in the long-term.

– Diet and Feeding

Both species are omnivorous, but they display a different feeding behavior. Guppies are surface eaters. They will swim to the water’s surface and consume the pellets or flakes before they sink, although many guppies will hunt the floating food as well.

The difference comes with the Siamese fish since they are bottom dwellers and will eat a lot of stuff by the time official feeding time has come. Siamese fish consume algae and plant matter primarily and food residues sinking in from the water’s surface.

However, this doesn’t mean you don’t need to feed them extra. It’s just that the risk of overfeeding is greater for them since you can’t tell how much they’ve eaten on their own. At the same time, feeding them too much will incentivize them to stop eating algae which contravenes their biological and environmental role.

Which have a scavenger fish that doesn’t scavenge? So, only provide your Siamese algae eaters with just enough food for them to consume in a minute or 2. Don’t use their appetite to tell you how much they should eat because their appetite is basically bottomless.

– Water Changes

Fortunately, you don’t need too many water changes since you already have Siamese fish to fulfill that role. Water changes aim to improve the water’s oxygen levels and dilute ammonia and nitrites that may accumulate due to fish waste and dead plant and animal matter.

The presence of the Siamese algae eaters will lower the need for too frequent water changes, thanks to their effect on the environment. That doesn’t mean you should skip this phase altogether. You still need to perform scheduled water changes, preferably once a week.

Don’t change more than 10% of the water, especially if you don’t have that many fish, to begin with. A 10 to 15% water change every 6-7 days is sufficient to rejuvenate the oxygen levels and keep the environment healthy and balanced.

– Number of Fish

How many fish you should have depends on the tank’s size, the fish’s size, and how the environment is set up, among other things. Guppies, for instance, do best in shoals of 5-6 members at a minimum. Siamese algae eaters also prefer shoals, but they can live on their own just fine.

Whatever the case may be, always consider the number of males when determining how many fish you will have. It’s the males that need limiting, not the females. Male guppies, for instance, can become quite territorial and will display aggressive behavior over food, hierarchy, and females. This can lead to constant fighting and bullying, sometimes with gruesome consequences. It’s not uncommon for guppies to nip at each other’s fins, leading to injuries, infections, and even death over time.

No matter how fish you plan on keeping, always try to stick by the 3-females-for-each-male rule. You can keep male-only tanks, but they need to be larger and more diverse in plants and decorations to provide more hiding spots. Such a setup will minimize fish stress and injuries that may occur due to bullying and fighting.

As for the Siamese algae eaters, you can keep 1 or 2 if you don’t want a larger group. They will do just fine, provided they have the optimal living conditions to feel comfortable long-term.

Do Siamese Algae Eaters Eat Baby Guppies?

Siamese algae eaters are primarily herbivorous but will consume protein sources occasionally when given the opportunity. These protein sources include guppy fry and other small fish babies, if any wander in their vicinity.

But it’s not the Siamese algae eaters that should concern you. I suggest focusing on guppies first since adult guppies are notorious for eating their own babies.

To prevent this issue, relocate the pregnant guppy female into a separate breeding tank and keep the fry there for at least 3-4 weeks. This is enough time for them to grow, gather their strength, and take care of themselves once in the main tank.


Although guppies and Siamese algae eaters are fairly different species, they have no problems cohabiting in the same environment. Provide each species with the optimal living parameters, limit the number of males, and learn their behavior and personalities.

Doing so will allow you to craft a stable and thriving aquatic environment for all fish to enjoy.

Updated: February 8, 2022
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