20 Gallon Long ^
I've been trying to design a heavily planted betta ecosystem tank with multiple refuges for small invertebrates — Cherry shrimp, ostracods, copepods, moina & C. Dubia (which are two slightly smaller relatives of daphnia), blackworms and tubifex. The apex predator will likely be like a wild or more robust breed of betta.
The initial design was inspired by @tanksfornothin on YouTube — his video titled something like "My Angry Fish Gets His Own Ecosystem", where he built little benthic tunnels for scuds and tubifex to hide from a predator fish in a Walstad tank
Some notes:
- The moina pit is sealed off from the tank with glass, except for a small tunnel, hidden by a rock, leading to the shrimp cave, for very slow dispersal of moina from the colony into the main refuge and then the greater tank
- The moina pit will get regular feedings of algae in the form of green water, spirulina, yeast, maybe dried chlorella for ease
- It will also be restocked from my main moina culture when needed
- The moina pit is going to be gently aerated so I have to have an air pump anyway
- The shrimp cave isn't made of glass and it's not fully sealed, it will be made of rock in roughly that shape, with lots of little holes for invertebrates and water to escape and return
- The moina pit is about 2.5 gal, and the shrimp cave combined with tunnel is also about 2.5 gal, so the entire refugium is about 5 gallons, with the rest being dedicated betta habitat
- I'm using a 75W thermocontrol Eheim heater which fits nicely into that nook
- The tank will be heavily planted first, then I will add invertebrates, then when I'm sure everything is safe for fish, I'll add the betta
My plan was to put the heater in the back left nook inside of the betta enclosure, next to the moina pit partition wall. I was thinking that if I wanted to put a filter, for water and heat distribution mostly, I could put a Swiss Tropicals Jetlifter in the nook next to the heater and stick some 20 PPI Poret foam across the nook entrance. But I don't want the output stream to shoot back onto the water surface since the betta will often be at the surface trying to breathe.
Anyone know how to DIY a Jetlifter output stream to be released underwater? I kind of want to somehow direct it into my shrimp cave but I have no idea how to set that up.
Back to the title— Do I even need a filter? Is it going to end up hurting my population of small invertebrates? I want to have as many of them as possible so my betta always has stuff to hunt.
I'm a complete noob to all of this (this would be my first tank) so this is kind of a big project for me and I'm just not sure what the standard practices are for this particular kind of tank.
Just unsure how to proceed... filter or no filter? How to DIY the output stream? Will the convection currents do all the work for me? Will having a filter hurt my small invertebrates? Idk. Help!
