What types of aquarium freshwater fish bury under sand ?

Most cichlids move sand or gravel around. However if you are doing your weekly water changes correctly you won’t have to get any cichlids to dig up your sand or gravel bed. You need to put your gravel vaccum all the way to the bottom of the sand bed and let the fast moving water clean the sand or gravel for you. Repeat this until the sand or gravel bed is clean.

Peacock eel will burrow him self under the sand most of the time. They are not to difficult to keep and make a nice addition if you have a larger tank and your fish are not too small, or he will eat them!

I’ve used sand on several occasions with different types of fish and I have never encountered this issue with poison gases. My other hole in your question is that if you did have anything in the sand and these gases were present, the first thing to die would be that animal. Incidentally most of the animals that practically live in the sand are kinda sensitive(such as loaches, clams, mussels, gobies and such) If you are having an issue with fish like these bottom feeders dying on you then most likely you do have a water quality issue. You need to keep up on your water changes. You can NOT use a gravel cleaner on sand. You would just **** all of it up and that won’t help you either. Hope all goes well.

im not sure for fresh but tropical
or if the temp of your tank is in the 75 to 80s
get cory cats or a coolie loach
i no you said you laoches but it dosent grow big and its cool cuz it moves like a snake

Bumblebee Gobies might bury in the sand…and yes they are freshwater. Many sites say that they are brackish, but they are truly freshwater. However, these are hard to find in most pet stores.

~ZTM