Computer fan placement?

[musamusa1975]

Hi
I’d appreciate some pointers where to place my computer fan in my fish tank that I’ve converted into a terrarium. Plants are sitting on a tray on stands above the water. RH is in the 90s and temps at 79 to 80. I hooked up the fan below the plexiglass which I’ve left open a crack for more circulation. I have it almost against the tank wall blowing against the wall. I was afraid if it faces the plants it would dry them out. But at RH in the 90s would it matter? I was thinking about placing it on the tray facing into the water as well, though I’d lose a a spot for a plant if I do that. Thanks for any thoughts.

 

[bluemax]

I have a similar set-up where I placed the fan on top of a tube of the same diameter. Then the fan blows down through the grate that makes up the false bottom of the tank and against the water. This increases humidity and circulation but doesn't blow against the plants. In a tank of the size you are using you might want to use a very low-output fan and/or keep it opened a bit.

 

[DragonsEye]

How large a tank is it?

In my 90gal I have several PC fans of various sizes. I have a couple smaller ones in the back right corner directed along the back and one in the back left corner dircted along a side facing the front. Plants in the fans' path do dry out faster. The fans are on a very low setting. (I use a variable AC/DC adaptor.) My goal was to create a very gentle "whirlwind". The wind is very light -- even my micromini plants barely move in the breeze -- but it does help keep the front glass from fogging up and keeps mold and algae growth down.

 

[specialkayme]

If you can swing it, these (https://www.amazon.com/dp/B01MZ6VNII?psc=1&ref=ppx_yo2ov_dt_b_product_details) with these (Magnetic Fan Mount 120 Mm for Ikea Greenhouse Cabinet - Etsy) work pretty good for me. Gives me the availability to direction the fan wherever I want, and vary the speed as much as I need.

I find that you usually need much more circulation than you originally think you need. And yes, it will cause the plants to dry out much more quickly that way. But keeps the mold growth down.

 

[musamusa1975]

How large a tank is it?

In my 90gal I have several PC fans of various sizes. I have a couple smaller ones in the back right corner directed along the back and one in the back left corner dircted along a side facing the front. Plants in the fans' path do dry out faster. The fans are on a very low setting. (I use a variable AC/DC adaptor.) My goal was to create a very gentle "whirlwind". The wind is very light -- even my micromini plants barely move in the breeze -- but it does help keep the front glass from fogging up and keeps mold and algae growth down.

Thanks. It’s about 22 inches long and maybe 15 wide if I remember.
Not a lot of space.

 

[musamusa1975]

If you can swing it, these (https://www.amazon.com/dp/B01MZ6VNII?psc=1&ref=ppx_yo2ov_dt_b_product_details) with these (Magnetic Fan Mount 120 Mm for Ikea Greenhouse Cabinet - Etsy) work pretty good for me. Gives me the availability to direction the fan wherever I want, and vary the speed as much as I need.

I find that you usually need much more circulation than you originally think you need. And yes, it will cause the plants to dry out much more quickly that way. But keeps the mold growth down.

Thanks.I’ll look into those.my system needs an upgrade