[AlbanyJ]

I am playing with the idea of using a 2.5 gallon tank as a cherry shrimp breeding tank. I would like to use as much of the equipment I have on hand rather than buying more for this tank. I have an 18 watt CF fixture that would fit beautifully over the 2.5g tank. If I use this little tank, it will be the smallest tank I’ve ever worked with (my primary tank is 90 gallons). I remember reading that the WPG rules go out the window with smaller tanks. However, after trying to search the nano and lighting forums, I couldn’t find the information on lighting for smaller tanks that I’m wondering about. If I set this little tank up, the tank will only have java moss and maybe a couple of anubius. My questions:
1. When, where and why do the WPG rules not apply for smaller tanks?
2. Is 18 watts above a 2.5 gallon tank too much (especially since I will only be keeping low light plants)?
Thanks.
jason

 

[sewingalot]

Post #21 will help you out a lot in this link: http://www.plantedtank.net/forums/lighting/85667-par-data-spiral-power-saver-bulbs.html

Actually, the whole thread is regarding a 2.5 gallon tank.

 

[paulrw]

i had pretty much the same setup. is the c.f. fixture 2x9w bulbs? thats what i used it was a Zilla fixture i believe it's made by coralife. if that is the case you will have an algae farm i ended up having the fixture hanging about a foot over the tank and had diy co2 diffusing through my canister filter and it still was way to much light i now have 1 13w cf hanging about 6" above the tank and i'm still battling algae. you might be able to hang the fixture even higher than 12" but it wasn't feasible for me. good luck!

also definitly read the link sewingalot provided it's got a lot of good info

 

[AlbanyJ]

Thanks sewingalot and paulrw. I suspected that lighting for a 2.5 gallon tank was more complicated than I've been used to. That's why I posted.

Indeed, the fixture I was thinking about using is a coralife 2 x 9watts. I might play around with this light (e.g., raising it, using only one of the bulbs) to see if it will work or look into finding a cheap desk lamp instead.

 

[rengb6]

It depends on what kind of plants you want to keep. I have a 2.5 and when it was a low maintenance tank I had 15 watts over it with java fern and java moss. Now I am experimenting with a high maintenance planted tank with CO2 and high light. I have 27watts over it and so far no major algae outbreaks(its been up for a little over a month). A popular desk lamp here on the forum is the 27watt hampton bay light that is found at home depot. I paid 20$ for mine and its perfect for growing high light plants like HC in a nano. Good luck whatever you decide to go with!

 

[cyfan964]

It depends on what kind of plants you want to keep. I have a 2.5 and when it was a low maintenance tank I had 15 watts over it with java fern and java moss. Now I am experimenting with a high maintenance planted tank with CO2 and high light. I have 27watts over it and so far no major algae outbreaks(its been up for a little over a month). A popular desk lamp here on the forum is the 27watt hampton bay light that is found at home depot. I paid 20$ for mine and its perfect for growing high light plants like HC in a nano. Good luck whatever you decide to go with!

I second the 27 watt daylight desk lamps. I bought mine from Wal-Mart. Around $20.

 

[mr.gaboozlebag]

1. When, where and why do the WPG rules not apply for smaller tanks?
2. Is 18 watts above a 2.5 gallon tank too much (especially since I will only be keeping low light plants)?
Thanks.
jason

The wpg rules are very misleading for ay size tank.You really need to judge by the dimensions of the tank. a deeper tank will need much more light, and better reflectors, while a very wide and low tank will need more spread out light, but not as intense. Also, some lights are more efficient than others, so you will get more light out of a metal halide than an incandescent.