Best Method for Replacing Substrate in Established Tank?

I want my 20 gallon fresh water aquarium to be more heavily planted. I started out several months ago with a large gravel substrate I thought looked nice. However, I don't think the large size is ideal for plants. I'm thinking about switching to a finer substrate such as Eco Complete. When I actually go to switch substrates, is there an ideal established method for making the switch? I read one article said to replace about 1/3 every 3-4 weeks. I can do this if I have to, but I'd rather get it all done at once. Also, if I'm using Eco Complete, should I layer it with other substrates? Like possibly put some of my larger sized gravel on top? Or is straight up Eco Complete ok?

Thanks in advance for any feedback. Always appreciate how friendly and helpful you guys all are...

 

It is slightly different, but when upgrading to a larger tank I moved everything from one tank to the other, but changed substrate (so the filter was already cycled for this bioload) and had absolutely no problems. I am not familiar with Eco Complete so I'm not the person to advise you on that, but if it were me I would simply swap them (but keep an eye on parameters as some beneficial bacteria does live in the substrate).

 

Eco Complete is supposedly not meant to be rinsed as it has beneficial bacteria in the bag but I always gave it a rinse before using it in my planted tanks. I only every used it on its own but you could mix in some gravel if you want to make the Eco Complete stretch a little further (although for a 20 gallon you won't need too much).

To switch out substrate I would remove any plants/driftwood/rocks/etc. and then siphon out the gravel (you'll probably need to shut off the filter and heater as this will also remove a decent amount of water). Then add the Eco Complete. I'd add it with a plastic cup/container and submerge it completely before pouring it out at the bottom of the tank. Then add your hardscape and plants back in and refill with dechlorinated water. Maybe let things settle for a while before restarting the filter so you're not pulling too much debris into it. The water should clear up in a few hours and you're done. Just keep a close eye on your water parameters for a couple of weeks.

Edit to add: you want to use a hose with a decent diameter to siphon out the gravel or it will get clogged. If your gravel is too large you can scoop it out instead (just the reverse of adding in the new substrate) but the siphon is much faster.

 

It is slightly different, but when upgrading to a larger tank I moved everything from one tank to the other, but changed substrate (so the filter was already cycled for this bioload) and had absolutely no problems. I am not familiar with Eco Complete so I'm not the person to advise you on that, but if it were me I would simply swap them (but keep an eye on parameters as some beneficial bacteria does live in the substrate).

Thanks for the tips!

 

Eco Complete is supposedly not meant to be rinsed as it has beneficial bacteria in the bag but I always gave it a rinse before using it in my planted tanks. I only every used it on its own but you could mix in some gravel if you want to make the Eco Complete stretch a little further (although for a 20 gallon you won't need too much).

To switch out substrate I would remove any plants/driftwood/rocks/etc. and then siphon out the gravel (you'll probably need to shut off the filter and heater as this will also remove a decent amount of water). Then add the Eco Complete. I'd add it with a plastic cup/container and submerge it completely before pouring it out at the bottom of the tank. Then add your hardscape and plants back in and refill with dechlorinated water. Maybe let things settle for a while before restarting the filter so you're not pulling too much debris into it. The water should clear up in a few hours and you're done. Just keep a close eye on your water parameters for a couple of weeks.

Edit to add: you want to use a hose with a decent diameter to siphon out the gravel or it will get clogged. If your gravel is too large you can scoop it out instead (just the reverse of adding in the new substrate) but the siphon is much faster.

Could I siphon most of my aquarium water into a temporary holding bin, then add fish to the bin, swap substrate, then re add water? Would keeping the old water help preserve the nitrogen cycle?

 

Look on youtube for videos. I saw a video sucking the gravel out with a normal old siphon. It was pretty easy looking. You wouldn't even have to remove your fish!

 

I don't know how to leave just a link. I searched switching substrates and it was a young boy on the video.

 

I don't know how to leave just a link. I searched switching substrates and it was a young boy on the video.

Cool! I'll keep that in mind! Thanks!

 

I always left the fish in the tank whenever I needed to switch substrates - it's just like a big water change for them. If you have particularly delicate fish or the water parameters (e.g. pH) in your tank are significantly different to what comes out of your tap it may be an idea to limit the amount of water being removed with the gravel. The bacteria are on surfaces though and not in the water column, so in my experience keeping the old tank water doesn't do much for the cycle. You are removing a lot of those surfaces with the substrate so it's still important to keep a close eye on the water parameters for the next couple of weeks in case of a mini-cycle.

 

I don't know how to leave just a link. I searched switching substrates and it was a young boy on the video.

Copy the http in your search bar when your on the video page then paste it into your post