If you’re planning to leave town for the holidays, a vacation, or any reason at all, the thought of leaving your aquarium behind can be a little stressful. 

Who’s going to feed your fish? Will algae take over? Will everything be okay when you get back? 

I just spent this past week getting my 5 planted aquariums ready for an 8-day Thanksgiving trip, and I’m here to show you exactly how I prepare my aquariums for when I’m not around. This guide will walk you through the steps I take leading up to a vacation and what I do the moment I return.

Whether you have one tank or several, these tips will help keep your fish, plants, and tank setup healthy while you’re away.

What to expect in your tank while you’re gone

Think back over the things you’ve done in your aquarium over the past week. You might have fed your fish, topped off your water, hopefully you did a water change, maybe you even trimmed your plants.

While you’re gone, you won’t be there to do any of that to your aquarium. If you were to go out of town right now with your tank as it is, here are some things you might come back to in 7 days:

Low water levels. Water evaporates pretty quick when it’s moving. Since you have a filter that’s designed to clean and circulate the water, you can expect around 1–2 gallons of water to evaporate in that week. More if you have high flow and warmer water. In my 40G breeder below, about 2 gallons of water evaporates between weekly water changes on Mondays. 

Your fish don’t get fed. Without you there, your fish won’t get fed. Don’t worry – unless you’ve been only feeding them once a week for the past months, they’ll be fine. They’ll snack on microfauna, algae, or leftover bits of food you might not see.

The steps I follow to get my tank ready

7 Days before leaving: start feeding more

A week before I leave, I start feeding my fish more frequently. Normally, I feed every other day, but during this time, I’ll feed daily to “bulk them up” a little.

This doesn’t mean overfeeding to the point of bloating—just enough to build up their reserves. Fish in planted aquariums aren’t going to starve while you’re away since they can graze on microfauna and algae. 

But going a week without food can still be stressful for them, so the extra feedings help them prepare. If you already feed your fish daily, upping their food amounts by 20% will accomplish the same goal. 

3 Days before leaving: small water change

By now, the extra feeding has likely increased the amount of waste in the tank. This is when I do a small water change, about 20-25%, to reset waste levels and reduce the risk of algae blooms while I’m away.

I also take this time to check all my equipment. Are the filters running smoothly? Are the lights on the right schedule? Is everything clean and in working order? 

Addressing any issues now avoids surprises later while you’re away and can’t deal with them. I can’t tell you the amount of times I’ve been gone for a week or more and I come back to cracked heaters, lights that haven’t turned off at all the whole week, and algae blooms as the result of that. 

So make sure you check all your timers and equipment!

24 Hours before leaving: big water change and final adjustments

The day before I leave is when I do a large water change, usually around 50% or more. This is a little bigger than my usual weekly water changes, and I make a few extra adjustments:

1. Overfill the tank: I fill the water level slightly higher than normal to account for evaporation. This keeps the filter intake and other equipment fully submerged while I’m gone.
   
2. Lower light duration/intensity: I reduce the lighting period by an hour or slightly dim the lighting intensity. I hate coming home to algae and this helps curb the growth of it without hurting your plants’ health.
   
3. Dose algaecides (optional): If I’m particularly worried about algae, I’ll use a quality algaecide like Green Water Labs Algae Control.

What about feeding while i’m gone?

For trips up to a week, I don’t use automatic feeders or have someone come over to feed my fish. 

In a planted tank, fish can forage on natural snacks like algae and microorganisms, which helps them stay healthy without overloading the tank with food.

If you’re gone for longer than a week, consider investing in an automatic feeder or asking a trusted friend to feed your fish. Be sure to portion out the food in advance to prevent overfeeding.

When I get back home

After a week away, the first thing I do after unpacking is check on all my tanks. I’m usually tired from the traveling, so this normally means just topping off my tanks with new water. 

I re-check all of the equipment, adjust the lighting to normal levels, feed my fish, and get back into my routine of water changes during that week. 

You might be able to do a water change and everything else I just mentioned above if you only have one tank, but I have 5 and doing all of them in an afternoon is too much. 

Prepping your aquarium for vacation doesn’t have to be stressful. With a little planning and some simple adjustments, you can leave your tank knowing with just a little bit more assurance that things will be okay while you’re gone. 

Whether you’re heading out for a holiday or just taking a break, give these steps a try. I hope they help. 

Happy scaping!

Dom