Why do I need current in a filterless tank?

[Ms.Bubbles]

Roan Art suggested I post my question again in this forum to get the lowdown from a few of the Plant Gurus...Here's my question:

I am seriously considering starting up a filterless, heavily planted tank (with very low fish load). I've read that going without a filter is possible, but that it's essential to have current in the tank, so at least an airpump is necessary (but I don't want even this).

Why is water current so essential in a (planted) tank? I've heard of many people keeping bettas in a planted, non-filtered tank, non-airpump tank, and they simply changed water every few days or once a week. Why is it possible to go without an airpump in this situation, and not the other???

 

[kyle3]

Talk to RTR about this-

you might look at his member page and give some of the info he has a read and then send him a question

- make sure you read tho so you don't ask a question he's already answered on his page

cheers
-Kyle

 

[rrkss]

I keep my betta in an unfiltered natural planted tank containing mostly low light plants that seem to be growing crazy getting about 2 hours of direct sunlight and the rest of their light from the ambient room light. This is a low tech tank and the betta is doing wonderful, water quality is perfect and the plants are happy. I assume the current is to promote oxygen exchange so the fish don't suffocate (plants only give off O2 in the daytime but consume O2 24/7). You relize that going this way requires a very low fish load to a high plant load. Maybe 6 whiteclouds maximum in a 55 gallon tank for example.

 

[Torf]

A small current in the water can help draw unfiltered water around the tank and increase it's chances of contacting the filtering media (plant surfaces). It can also help with temperature control.

 

[OrionGirl]

Currents meet a number of needs--oxygenation through gas exchange at the surface, temperature equilibrium being the 2 most concerning aquariasts. If you use a substrate heater, benefiical to the plants as well as creating convection currents to slowly move water, you should be okay. I'd still go with light stocking, and monitor, monitor, monitor before trusting the setup to fish. I'd probably have 2-3 thermometers spread throughout the setup, and make sure they were all within 2-3 degrees of each other.

And, the difference between what you're doing and an unfiltered, unheated betta bowl is that you want a setup that will be healthy. Bettas in unheated, unfiltered bowls are often very unhealthy and short lived. By my definition, that means they don't 'work'--but I know that a betta should live for more than a year.