Too much/too little light?

[Josh Q]

I am building hoods with lights for a regular 10G tank and a tall 18G tank. Both have the same dimentions (sp?) as far as length and width so I'll be able to build the same hood for both. My question is, for the 18G I was planning on using two 18" 15 watt full spectrum flourecent bulbs. Is that enough light to have plants in there? I'm not going to have a LOT of plants but I want enough to look good/natural. Second question is, would those same two lights be too much light for the 10G tank? I want this one to be heavily planted and it will only have 2-3 fish in it. Thanks.
-Josh

 

[cichlid_freak]

I'm useing two 18" light fixtures on my 10 gal., but that is because I have a lot of red plants, like my red tiger lilly that I had to nurse back to health. I don't believe that amount of light is NEEDED, but it really depends on your ocupants. Dark green plants need the least, by a general rule, and red plants need the most. I LOVE my red plants, I just got two more lilly bulbs from my LFS for free I really look forward to helping him setup his new fish/plant shop. Summer work is so much fun for me, and I get paid for it too.

 

[Jimthefish]

Two tubes would be fine for both but add reflectors for the 18 gall. You could even go for one tube in the 18 and concentrate on plants that need less light like java moss and fern, anubias and some crypts.

 

[Great Lakes]

Remember, I am the "never enough light" guy.

Two over the 10 gallon would be great. I think the depth of the 18 will get you though. I would fit this one with three to four bulbs. Set timers on them with two on for total duration, and the other two for a shorter span during the day. This also more closly simulates natural light.

 

[catman]

As a general rule, i use 2 watts per gallon.

I always add reflectors!

 

[Josh Q]

Well I've decided that the 10 is getting two tubes and the 18 getting four. I've already built the 10G with galvanized steel for reflecting the light and will do the same for the 18. Thanks guys/girls.
-Josh

 

[GraemeK]

i wonder if anyone can help me as my question is similar.
my tank is a tropiquarium 88 by hagen. it has 2 x 24" 20w tubes. the tank is 33" long, 15" wide and 18" tall with about 3" gravel at front and 5" at back.
The tank is well planted but obviously i hope for the plants to grow more. I leave the lights on for 10 hours a day at present as 12 caused algae growth.
The hood where the tubes are is white so there is a certain amount of reflection. the tubes i have (on saturday) are power-glo's which are the brightest i can get!

is this enough for decent plant growth? combined with good feed? i'm thinking about a CO2 system soon also.
if my problem is light how can i increase it? the hood is custom to the tank and i cant add more tubes? maybe shine lamps in from the sides?

thank you....

p.s the tank appears to be very bright as it is

 

[LesGerber]

Great Lakes, Since you are the "Not enough light guy" I seen something that you would love It was a 48 inch light strip that cranks out over 220 watts of white and blue light. I would have got it but the thing costs 400.00 US so I guess I better figure a DIY system for my tank.....lol



Les