The best way to change your substrate with fish in the tank

Changing your substrate can be a time-consuming task especially if you have a lot of fish in the tank. In this guide on how to change aquarium substrate with fish in tank, I will show you what I have found to be the easiest and fastest way to change the substrate.

Steps to changing the substrate without removing the fish

Step 1: Turn off your filter and pumps

You do not want your filter and pumps running while changing the substrate. This will lead to them getting clogged up and being unable to use them effectively.

Step 2: Remove all your decoration from the tank

When scooping up the old substrate from your tank, you do not want to have to work around the decorations in the tank. The best way to remove them is to get a bucket that you can just put them in without worrying about dripping water all over.

Step 3: Vacuum your old substrate

I know that this may sound counterintuitive to clean the substrate if you are going to be removing it, but it is an important part of keeping your tank clean. Vacuuming your gravel first, you get everything out before it clouds your water.

Step 4: Remove your old substrate

I have found that using a large strainer or fish catcher that is sturdy is the best way to remove the old substrate. You do need to be careful not to catch any fish. I like to keep a 5-gallon bucket handy to put all the substrate in. This way, I can verify that there is no fish in it, and it tends to make less of a mess.

Step 5: Turn the pumps back on and let your tank sit for a little while

Removing your old substrate is going to cloud the water. You want to get as much of the old debris and fish waste out as possible before you add your new substrate. You should let the pump run for at least an hour or more to get the water as clean as possible.

Step 6: Clean your new substrate:

While you are waiting for the water in your tank to clear up, now is the perfect time to clean and rinse your new substrate. You should rinse it with clean water a minimum of 3 times to get all the dust and chemicals out of it.

Step 7: Add your substrate back into your aquarium.

To add your substrate into the aquarium, dump it in or use a scoop to put it in an even layer. Make sure you do not crush any fish when adding your new substrate.

Can you change the substrate in a planted tank?

It is very easy to change the substrate in a planted tank and it should be done when it is obvious that your plants are not getting enough nutrients from their current substrate source. To change the substrate in a planted tank you need to remove the plants first and replace the substrate. Your water is going to get cloudy, and you will need to change your filter media multiple times to get all the cloudy substrate out of the water.

Can you change gravel with fish in the tank?

You can change the gravel with fish in the tank by making sure that your filter is off and you have removed all the decorations in your tank. Your fish will get stressed out by changing the gravel but not as stressed out as they would get if you had to catch them with a net first.

How often should you change the substrate in your tank?

You only need to change the substrate in your tank if you have a planted tank or have a water quality issue and can not get the ammonia levels down. Sometimes when the substrate in your tank gets dirty, and a lot of uneaten fish food and fish waste gets into your tank, the only way to get the ammonia levels down is to replace your substrate.

Can I add substrate with fish in the tank?

You can add substrate with fish in the tank as long as you are careful not to crush any fish. You should add small amounts at a time making sure to not disturb the fish too much or your plants.