Hi everyone, I'm new here.
I've had my 10 gallon tank for almost a year now, with a betta in it. I think I've got a good grasp on taking care of him - he's still doing well. My tank's established, with 0 ppm ammonia and nitrites, and 10 ppm nitrates. It's mainly got artificial decorations and some gravel, but we're planning to change that now. We're switching to real plants and sand as our substrate. I'm excited about the changes, but I've got some questions.
What'll happen to the tank's bacteria, and how do I change the substrate without messing up the cycle? Also, what plants are best for a betta tank, and how do I keep them healthy? I'm not really sure where to start.
changing substrate in an established aquarium
Re: changing substrate in an established aquarium
To maintain your beneficial bacteria, I'd suggest putting some of the old substrate in a panty hose and leaving it in the tank, on top of the new sand. This way, the bacteria can transition smoothly. Just be sure to keep the hose in tank water when you switch to sand. You can remove it after about six weeks. For plants, bettas aren't too fussy, but they do love to sit in floating ones - it makes it easier for them to get to the surface for air. I've had good luck with floating anacharis, and my betta loves to hide in it. I also keep amazon sword and anubias in my tank, and they work well. Water lettuce is another great option - the big type, not dwarf - it grows these beautiful long roots that bettas love to play in. Just be careful not to let it take over the whole tank, or it'll block light for other plants and use up too much oxygen. I like to let it cover about half the top.
Re: changing substrate in an established aquarium
Welcome to TFF.
In an established aquarium like yours, bacteria are present on every surface, forming what's known as a biofilm. While a lot of attention is focused on nitrifying bacteria that convert ammonia to nitrite and then to nitrate, this is only a small part of the bacteria ecosystem. The filter does hold a significant amount of nitrifying bacteria, but there's also a substantial colony in the substrate, and other essential bacteria species are primarily found in the substrate. So, you're right to think of the substrate as the primary bacteria bed.
Changing the substrate will inevitably disrupt this bacteria bed, and it's not possible to "keep" the substrate bacteria when making the switch. However, in a 10g tank with a single Betta and live plants, this shouldn't cause issues with the cycle. The plants will efficiently handle any ammonia, converting it without producing nitrite or nitrate. As a precaution, keep the filter wet in tank water to preserve most of the bacteria, particularly the nitrifying ones.
Bettas appreciate having floating plants around them, so be sure to leave some open water between the plants or their leaves. For lower plants that are planted in the substrate, you have some flexibility. Plants that thrive in lower light conditions work well when paired with floating plants that can provide shade for the lower area - your Betta will appreciate this too. Java Fern and Java Moss are great options for low-light plants that can be attached to wood, rock, or other decorations. Water Sprite, Frogbit, and Water Lettuce are all excellent floating plants to consider.
In an established aquarium like yours, bacteria are present on every surface, forming what's known as a biofilm. While a lot of attention is focused on nitrifying bacteria that convert ammonia to nitrite and then to nitrate, this is only a small part of the bacteria ecosystem. The filter does hold a significant amount of nitrifying bacteria, but there's also a substantial colony in the substrate, and other essential bacteria species are primarily found in the substrate. So, you're right to think of the substrate as the primary bacteria bed.
Changing the substrate will inevitably disrupt this bacteria bed, and it's not possible to "keep" the substrate bacteria when making the switch. However, in a 10g tank with a single Betta and live plants, this shouldn't cause issues with the cycle. The plants will efficiently handle any ammonia, converting it without producing nitrite or nitrate. As a precaution, keep the filter wet in tank water to preserve most of the bacteria, particularly the nitrifying ones.
Bettas appreciate having floating plants around them, so be sure to leave some open water between the plants or their leaves. For lower plants that are planted in the substrate, you have some flexibility. Plants that thrive in lower light conditions work well when paired with floating plants that can provide shade for the lower area - your Betta will appreciate this too. Java Fern and Java Moss are great options for low-light plants that can be attached to wood, rock, or other decorations. Water Sprite, Frogbit, and Water Lettuce are all excellent floating plants to consider.
Re: changing substrate in an established aquarium
I concur with the suggestions above. I've had success with a planted or silent cycle approach when starting a new tank. This method relies on having sufficient plants to handle the ammonia produced by the fish. With a single Betta, this should be relatively straightforward. I've found that caring for floating plants and ferns is a breeze. They absorb the necessary nutrients from the waste in the water, as well as any leftover food that decomposes. You can also supplement with products like flourish if desired. For rooted plants, plant root tabs placed near the roots can be beneficial. However, it's essential to prioritize floating, fast-growing plants, as they utilize the most ammonia quickly.
Re: changing substrate in an established aquarium
Hi everyone, I'm new to the forum.
Re: changing substrate in an established aquarium
Thanks for the encouragement. I'll definitely send pics once we're all set up. As for the substrate change, I'm still a bit unsure about the process. Should I just go ahead and vacuum out all the gravel at once, or is it better to do it in parts? I'm thinking of keeping the filter in place since that's where most of the bacteria should be, but I want to make sure I'm doing this right.
Re: changing substrate in an established aquarium
You can definitely change it all at once, just make sure to have those fast-growing floating plants in the tank to absorb the ammonia.
Re: changing substrate in an established aquarium
@oldraider @boomer @Deanasue
I'm thinking of changing the substrate all at once - so I'll need to have some live plants ready to go in at the same time, right? I'm just a bit worried about the uneaten food and any ammonia that might be left in the gravel, should I do a water change before or after I switch to the sand? And will the tank need to re-cycle again, or will the plants and the filter be enough to keep everything stable?
I'm thinking of changing the substrate all at once - so I'll need to have some live plants ready to go in at the same time, right? I'm just a bit worried about the uneaten food and any ammonia that might be left in the gravel, should I do a water change before or after I switch to the sand? And will the tank need to re-cycle again, or will the plants and the filter be enough to keep everything stable?
Re: changing substrate in an established aquarium
You'll want to keep your filter media wet in tank water in a bucket while you're switching out the substrate. That way, you can minimize the disruption to the beneficial bacteria. Once you've got the tank filled back up and dechlorinated, just place the filter media back in the filter and turn it back on.harvest wrote: ↑Mon Apr 28, 2025 3:51 pm Hi everyone, I'm new here.
I've had my 10 gallon tank for almost a year now, with a betta in it. I think I've got a good grasp on taking care of him - he's still doing well. My tank's established, with 0 ppm ammonia and nitrites, and 10 ppm nitrates. It's mainly got artificial decorations and some gravel, but we're planning to change that now. We're switching to real plants and sand as our substrate. I'm excited about the changes, but I've got some questions.
What'll happen to the tank's bacteria, and how do I change the substrate without messing up the cycle? Also, what plants are best for a betta tank, and how do I keep them healthy? I'm not really sure where to start.
Re: changing substrate in an established aquarium
I'm still a bit unclear on the process. When you say I should change the substrate all at once, do I do a large water change to remove the gravel and then add the sand? Should I save some of the aquarium water to maintain the beneficial bacteria? And what about the live plants - do I add them before or after the substrate change?harvest wrote: ↑Mon Apr 28, 2025 3:51 pm Hi everyone, I'm new here.
I've had my 10 gallon tank for almost a year now, with a betta in it. I think I've got a good grasp on taking care of him - he's still doing well. My tank's established, with 0 ppm ammonia and nitrites, and 10 ppm nitrates. It's mainly got artificial decorations and some gravel, but we're planning to change that now. We're switching to real plants and sand as our substrate. I'm excited about the changes, but I've got some questions.
What'll happen to the tank's bacteria, and how do I change the substrate without messing up the cycle? Also, what plants are best for a betta tank, and how do I keep them healthy? I'm not really sure where to start.