My Experience with the Eheim Automatic Fish Feeder

As someone who's been keeping fish for years, I've always struggled with that familiar dilemma: what do you do with your aquatic friends when vacation calls?

After doing my homework and reading through countless reviews, I decided to give the Eheim 3581 automatic fish feeder a shot. Here's my honest take after using it for several months.

What Actually Works Well

I'll start with the positives because there are quite a few. The digital programming is surprisingly intuitive once you get the hang of it – though I'll admit I had to pull out the manual more than once initially. The battery-powered design is brilliant; no messy cords to deal with or worry about power outages while you're away.

The build quality feels solid in your hands. At 9.2 ounces, it's got enough weight to stay put without being cumbersome. The rotating drum mechanism is clever and reliable – I've watched it cycle dozens of times and it's consistent every single time. The little fan that keeps food dry is a thoughtful touch that prevents those frustrating jams.

Programming for 1-4 feedings per day gives you flexibility, and the manual feed button is invaluable for testing. I probably hit that button 20 times during my initial setup just to make sure I had the portion size right.

The Frustrating Parts

Here's where I need to be honest – this feeder has some quirks that can drive you nuts if you're not prepared for them. The biggest issue for me has been portion control. Even with the dispensing door adjusted to its smallest opening, it still dumps more food than I'd like for my smaller tank. I ended up using electrical tape (as suggested by other users) to secure the door position, which helped but didn't completely solve the problem.

The size is another pain point. This thing is chunky – clearly designed with larger tanks and even turtles in mind. If you're running a nano setup like I am, finding space for it becomes a real puzzle. I had to rearrange my lighting just to make it fit properly.

The programming has a gotcha that nearly cost me a vacation disaster: after setting feeding times, you MUST select how many drum rotations you want (one or two arrows on the display). Miss this step and your fish don't get fed – period. I learned this the hard way during testing, thankfully not while I was actually away.

Real-World Performance

I've used this feeder for multiple week-long trips now, and it's never failed to feed my fish. That reliability is worth its weight in gold when you're 500 miles away wondering if everything's okay at home. The 100ml food capacity is genuinely huge – I could probably go a month without refilling it.

However, I do think it overfeeds slightly compared to my manual feeding. My fish are definitely well-fed when I return, and I usually need to do a more thorough water change than usual. It's not terrible, but it's worth factoring into your expectations.

The Bottom Line

Despite its flaws, I'm genuinely glad I bought this feeder. The peace of mind it provides during vacations is invaluable. Yes, it's oversized for smaller tanks. Yes, the portion control could be more precise. But when it comes to the core function – reliably feeding your fish when you can't – it delivers.

If you're considering this feeder, here's my advice: buy it well before you need it. Spend time testing and adjusting. Start with fresh batteries. And don't expect perfection – expect reliability, which in the fish-keeping world is often more important.

Rating: 7.5/10 – A solid, dependable feeder that gets the job done, even if it's not perfect for every setup.

Note: If you have a nano tank and portion control is critical, you might want to look at alternatives like the Fish Mate F14 that some users swear by for smaller, more controlled portions.