25 Gallon Cube Substrate Choices

We’re starting a 25 gallon cube with 5 otos and 5 glass catfish. We’re currently going back and forth on the substrate. We plan on making the bottom sort of look like a river so we have blue smooth rocks for the center and we want black on the outside. We’re deciding between fine sand, UNS Controsoil Black pellets, and Carib Sea Eco Complete. With sand, our concern is the plants won’t grow so I think we’re moving away from that but I’ve read the pellets are good for plants as well as the Carib sea. Our concern with both is we don’t want our otos ending up with scratched tummies. So if anyone has opinions on these choices please let us know.

Additionally, any tips are welcome, including how to cycle a freshwater tank. I’m used to having saltwater so this is new for me.

 

substrate is up to you. just be warned that aquasoil starts to fall apart after a few years, so you will need to replace it every so often. you can grow things in sand if you use root tabs. Not sure about putting glass catfish in a 25 gallon cube. cycling a freshwater is the same as cycling a saltwater tank, btw.

 

substrate is up to you. just be warned that aquasoil starts to fall apart after a few years, so you will need to replace it every so often. you can grow things in sand if you use root tabs. Not sure about putting glass catfish in a 25 gallon cube. cycling a freshwater is the same as cycling a saltwater tank, btw.

Fantastic. Thanks a ton! Another concern I have with the sand is that it’ll starve the plants from water. Will the plants get water fine?

 

1. Sand is fine for plants. While a few may benefit from adding root tabs, most will get their nutrients from the water column. I have either pool filter sand or Black Diamond sandblasting sand (depending on what color I wanted) in all 10 tanks, and they're all at least moderately planted.
2. You mentioned fine sand. I'd be careful of that. If it's too fine it will constantly be stirred up, and may cause problems with vacuuming and with getting into your filter.
3. I'm a big fan of pool filter sand. It's heavy enough to not cause the above mentioned problems, is relatively inexpensive, and needs little to no rinsing. Using a smaller vacuum tube I can even stick the end down into the sand to get gunk. The sand will come about halfway up the tube
4. You mentioned getting otos. They don't really spend that much time on the substrate. They eat biofilm, so will spend much of their time on the glass, plants, decor, etc. Also, they can be difficult to get acclimated, and you may already know this, but they should only be introduced to well established tanks (again, they eat biofilm, and that takes time to build up).

. . . and welcome to the forum.

 

Fantastic. Thanks a ton! Another concern I have with the sand is that it’ll starve the plants from water. Will the plants get water fine?

Maybe stroll in nature once in a while and see in which conditions marsh plants grow (most plants in our hobby are marsh plants). Sand is just fine.

 

Sand is fine for plants, it needs to be stirred occasionally to prevent clogging. Some small snails can do this nicely for you but they might overpopulate without assasin snails or other predators if any overfeeding happens

 

1. Sand is fine for plants. While a few may benefit from adding root tabs, most will get their nutrients from the water column. I have either pool filter sand or Black Diamond sandblasting sand (depending on what color I wanted) in all 10 tanks, and they're all at least moderately planted.
2. You mentioned fine sand. I'd be careful of that. If it's too fine it will constantly be stirred up, and may cause problems with vacuuming and with getting into your filter.
3. I'm a big fan of pool filter sand. It's heavy enough to not cause the above mentioned problems, is relatively inexpensive, and needs little to no rinsing. Using a smaller vacuum tube I can even stick the end down into the sand to get gunk. The sand will come about halfway up the tube
4. You mentioned getting otos. They don't really spend that much time on the substrate. They eat biofilm, so will spend much of their time on the glass, plants, decor, etc. Also, they can be difficult to get acclimated, and you may already know this, but they should only be introduced to well established tanks (again, they eat biofilm, and that takes time to build up).

. . . and welcome to the forum.

Hey - Thanks for the in-depth explanation.
After purchasing black diamond fine sand, we saw your post so I think we’re going to return it and go back for the medium. We may introduce cories at some point but we’ll have to see how the bio load does so we wanted to get a soft sand for them as well. As far as otos, we can wait on them. We don’t plan on actually starting the tank until we get back from our vacation Memorial Day weekend. We have to cycle the tank first. We want to get the shrimp, the glass catfish in there first, then the otos. Hopefully by the time we get to the otos everything will be set by then but we don’t plan on introducing anything until the parameters pass the tests.

Sand is fine for plants, it needs to be stirred occasionally to prevent clogging. Some small snails can do this nicely for you but they might overpopulate without assasin snails or other predators if any overfeeding happens

Yeah we plan on doing some snails. I had a solid colony of those guys in my saltwater before I gave up the hobby and boy can they multiply.

 

Sand is fine for plants, it needs to be stirred occasionally to prevent clogging. Some small snails can do this nicely for you but they might overpopulate without assasin snails or other predators if any overfeeding happens

Hey - Thanks for the in-depth explanation.
After purchasing black diamond fine sand, we saw your post so I think we’re going to return it and go back for the medium. We may introduce cories at some point but we’ll have to see how the bio load does so we wanted to get a soft sand for them as well. As far as otos, we can wait on them. We don’t plan on actually starting the tank until we get back from our vacation Memorial Day weekend. We have to cycle the tank first. We want to get the shrimp, the glass catfish in there first, then the otos. Hopefully by the time we get to the otos everything will be set by then but we don’t plan on introducing anything until the parameters pass the tests.

Yeah we plan on doing some snails. I had a solid colony of those guys in my saltwater before I gave up the hobby and boy can they multiply.

I really like snails myself , I have some nerite snails and bunch of 'pest' snails. I think they are all useful in their own way

 

Sand is fine for plants, it needs to be stirred occasionally to prevent clogging. Some small snails can do this nicely for you but they might overpopulate without assasin snails or other predators if any overfeeding happens

I really like snails myself , I have some nerite snails and bunch of 'pest' snails. I think they are all useful in their own way

I just enjoy seeing them nom on the side of the glass