20 gallon long tank and 3 aquaclear 20 filters?

[Dano83]

Hello,

I currently have two aquaclear 20 filters on my second tank at the ends but the middle of the tank has no water movement. I want to create a small current for the zebra danios I will be getting.

Would this be ok for them?

 

[Whitecloudminnowguy09]

Airstone could work, but I have heard of people using three aquaclears, too. But an airstone might save money. I personally would go for an airstone, but up to u imo!

 

[Dano83]

I'm planning on adding some water wisteria to the tank also. Would the airstone remove some of the co2 in the tank?

 

[fishorama]

I have 2 ACs on a 20long. I think mine are 30s or 50s. Try just moving them toward the middle at little bit. You know you can adjust the flow by moving the intake, right? Toward the media box for full flow, away to slow it (I think, but I may have that backward).

I don't think danios will mind a calmer area to rest in. Mine liked to play in the rollercoaster of flow between 2 ACs (bigger tank, bigger filters). Your wisteria might like a calmer area too.

 

[Whitecloudminnowguy09]

High levels of water agitation will cause CO2 to gas off quicker than if the water's surface is unbroken, but honestly in my experience I would not think it would be a problem. I have seen one person say, "I have run airstones in CO2 injected tanks and still gotten excellent plant growth and pearling."It also is quite unhealthy for a tank to have zero break in surface tension. Gas exchange is necessary.
Imo

 

[Colin_T]

One AquaClear HOB filter should provide sufficient current for danios in that tank.

You don't want the fish to swim into currents continuously. They don't do it in the wild and shouldn't be forced to do it in captivity. In the wild they have strong moving water they go through to get to calmer areas (usually pools). In an aquarium you can have a small powerhead on a timer and have it come on for an hour once or twice a day. The fish will swim in that and can rest after.

 

[Bamf Comics]

General math used to be that all your box advertised flow rates combined, divided by your tank's raw gallonage should end up in the 6 to 12 times range. High for your river types, less for slow water lovers. You can even have larger tanks with zones so the fish have options. For instance, adding a 300+ filter to a 55 on one side. People do it and it offers flow rate diversity. I'm more a fan of a couple 300's split to each side for most of my needs. Two Emperor 280 types instead of one Emperor 400. They still make those right? Tank in a box kits usually only have one filter as well.