How To Clean Your Tank With Fish In It (Without Killing Them)

How To Clean Your Tank With Fish In It (Without Killing Them)

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The easiest way to clean your aquarium is with the fish inside the tank. Though this can be at times unsafe, especially if you accidentally place items that are not fish safe or that alter your water chemistryin the tank.

If things like detergents, chlorine or cleaners like bleach find their way into your aquarium, they will very likely kill your fish in large numbers.

So, how do you clean a fish tank with your fish inside, making sure they remain safe throughout the process.

Probably the first and most straight forward way is to install a filter that has biological, mechanical, and chemical media. You also want to keep dirt from accumulating in you water column as much as possible, so, add aquarium plants and cleaners like snails, shrimp, and bottom-dwelling fish like cories, kuhli loach, and bristlenose pleco.

Another valuable hack is to invest in aquarium cleaning tools like a gravel vacuum and algae scraper, plus stock up on fish-safe cleaning remedies like white vinegar, which are safe even when they find their way into the tank.

Avoid any chemicals that are not rated for aquarium use, and be sure to rinse decor, plants, and rocks you’ve cleaned with bleach or hydrogen peroxide outside your tank.

Please read on for better insight on this topic.

Do You Need To Move Your Fish When Cleaning The Tank?

No, to clean your aquarium, you should never have to remove your fish, it’s actually not advisable. Removing the fish will shock your system, which is something you don’t want to happen.

Moving the fish will also be quite stressful to you and the animals.

On your part, you need to find them a new home with similar conditions to what they are used to in the old tank. Then you need to catch and move your fish as gently as possible making sure you do not stress them.

The new tank also needs to be fully cycled, with a filter, heater, and an air pump installed, though the latter is optional if filtration system will create enough agitation in the water.

To top on the hassle, you may need to remove filters and heaters from your old tank before you try catching your fish, and later remove your plants, decor, and rocks as well.

On how to clean your tank without moving your fish? See below!

How To Clean Your Tank With The Fish In It (5 Effective Tips)

One main reason you do not want to remove your fish when cleaning your tank is that the activity is quite regular, sometimes happening weekly or bi-weekly. The frequency is simply too routine to achieve even in theory.

So leave your fish in the tank and…

Hack #1 — Do Regular Water Changes

Change 10 to 15 percent of your water every week to help expel excess dirt, including ammonia and nitrates from your tank. But if you have a fairly clean tank, you can stagger the schedule and instead do 20 to 25 percent water changes every two weeks.

Make sure that the conditions of your water column remain the same even after the water change. As such, it is useful to note that maintaining your water parameters is especially a challenge if you decide to go the 25 percent route.

Ideally, you want to make sure the water you use to refill your tank has a temperature and ph akin to the column already in the aquarium. To do this, use lukewarm water to fill a tropical fish tank, albeit cold water is Ok when keeping fish that prefer water on the cooler side.

Another thing you do not want in your tank is excess dissolved elements and chemicals like chlorine, so consider using RO water during your water changes.

Check your water parameters after every water change to make sure all conditions are stable and use a water conditioner or clarifier for a crystal clear fish tank.

Hack #2 — Vacuum Your Substrate

Your substrate harbors the most dirt in your tank, even more than plants, rocks, and driftwood. You therefore want to keep it clean by vacuuming it regularly.

Luckily, using a gravel siphon kit is the furthest thing there is from technical. You only need to pass it over your substrate making sure you target any visible dirt patches and debris.

That said, your substrate can also help clean your tank on its own because healthy bacteria build up on there. But good bacteria will only accumulate if there is good water circulation delivering oxygen to the base of your tank.

Vacuuming your gravel will help water get into compact pockets that form in the substrate discouraging anaerobic (bad bacteria) and help aerobic (good) bacteria to dominate your tank.

In case you have a challenge with your water and substrate agitation, consider getting an air pump or an under gravel filter.

Hack #3 — Clean Your Aquarium Filter Media

If you do not have a schedule for cleaning your tank filters already, you may want to start by establishing one. I recommend cleaning the filter media at least once every month, coupled with a large water change.

Ideally, this monthly cleaning should also include vacuuming your gravel and washing your plants, decor, and aquarium glass. If you need to change your filter media, it would be wise to do that at that time.

Please read this article for more insight on how and when to change your filter media.

One thing you will learn from the post recommended above is that cleaning your filter is not as straight forward as cleaning other pieces of your aquarium. Essentially, you should not clean too thoroughly and not too often, this ensures the beneficial bacteria responsible for purifying your water remain intact.

As much, cleaning your filter media in aquarium water is recommended as opposed to using clean water from another source.

For that reason, I would recommend reading this article as well in case you need more insight into how often and how to clean your aquarium filter media.

Hack #4 — Bleach Your Plants

I have seen many aquarists who are not very convinced that bleaching their plants and decor is safe for fish, but it is. Bleach is especially helpful when dealing with algae and parasites in your tank.

All you have to do is ensure your plants are thoroughly rinsed before you reintroduce them into your fish tank.

Alternatively, you can opt to use vinegar to clean plants and decor as it is safer and perfectly Ok should it get into your tank by accident. Still, make sure you use vinegar sparingly as too much will buffer you aquarium ph, something you do not want, especially with sensitive tropical fish like discus.

Bleach dip your plants for five (5) minutes in a concentration with one part bleach and 19 parts water. In case you have fragile plants like dwarf water lettuce, a three (3) minutes dip is better to clean them, but also keep the plants alive.

Moreover, you can use hydrogen peroxide to remove algae or potassium permanganate to clean snails on plants. Please more info in this post.

Hack #5 — Use Algae Scraper (+Vinegar) on Your Glass

The last tips for cleaning your tank with fish inside is with regard to glass surfaces. This is especially important because algae notoriously hang on the wall and can be quite hard to get off.

Another common challenge, more so on aquarium covers is limescale, which appears as a white film on the surface.

But not to worry, because armed with an algae scraper and a little vinegar, you can easily remove most grime from your glass with minimal stress to the fish.

Starting with your cover, splash a little vinegar solution from a spray bottle on your aquarium lid, then use an old (but clean) toothbrush to scrub any white residue on the glass. For better results, target the calcium patches directly.

Once you’ve removed all the limescale, you can do a final wipe with an aquarium sponge or algae scraper for a finer finish.

The scrapers also come in handy once you move to clean your fish tank walls, particularly when you have algae of whichever kind on there; including green spot algae.

Using an algae scraper correctly is mostly straight forward as most come along with instructions, plus honing the skill is pretty much intuitive much like using a scouring pad in your kitchen.

However, make sure you get a new algae scraper once every year especially if you use it too often because their effectiveness diminishes with time.

In conclusion, here is the last post I would recommend you read, particularly useful when you need to clean white grime from your aquarium glass.

Eddie Waithaka

Resident Content Creator and Marketer at AquariaWise who talks about aquariums and fish and aquascapes a lot.

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