How much surface agitation

[Tropical Tony]

Hi guys. At the moment I have a 150l planted tank. I’ve got a box filter (what come with the tank) and an external filter. They are both running at the same time but I’m almost ready to take the box filter out and just let the external do it’s thing. My question is how much surface agitation should I have for my planted tank? The box filter sits High at the moment and provides good agitation however when I turn it off the external doesn’t seem to be aggitating it as much.

 

[Byron]

You do not want a lot of surface disturbance as it can drive out CO2 that the plants need during daylight. At night it is a bit different story; you want to bring in oxygen for the fish, but you do not want to drive out too much of the CO2 which builds up during the darkness in order to provide sufficient CO2 during the daylight. The degree of planting and the fish load factor in.

 

[Tropical Tony]

So as my box filter is still running you can really see the surface getting agitated. When it’s switched off and just the external running it’s a really light swirl. Is this ideal?

 

[Byron]

So as my box filter is still running you can really see the surface getting agitated. When it’s switched off and just the external running it’s a really light swirl. Is this ideal?

I would need to see the tank. It depends upon the number of plants and the fish load, and the surface agitation.