Light Intensity?? how much is too much??

[mccidlee]

My 20g tank now has
2 X 18W Compact Fluorescent
2 x 15W T-8 Fluorescent
However, I am not happy with those two T-8 and thinking to replace them with power Compact Fluorescent.

But the question I have now is should I go with 1 X 36W and make the total Watt 72W (2 X 18 + 1 X 36), or I should go with 1 X 55W and get the total 91W.. is 91W too much for a 20g tank...

And also one more thing: 5500K or 6700K(6500K)?? those 18W I have now are 6500K, should this time I do with 5500K??

Any advice will be appreciated...

 

[farm41]

I have 4 F17T8/TL950 on my 20H, at 5000K, I like the look of the 5000K, I have the 5000K on all my planted tanks.

It is purely a matter of your liking, the plants and fish won't care which light you use, of course the plants would grow more with more watts.

 

[mm12463]

The one thing to consider is the more light you have the more potential there is for things to go right and wrong.

The more light you have the faster the plants will grow. The faster they will consume the nutrients in the water. Overdose, under dose, CO2 poops out and things aren't nice anymore. Algae can start to spring up overnight if you don't pay attention. High light requires more time on part of the hobbyist paying close attention. Plenty of people do it but they have committed to that path.

Basically you need to think about your goals, how much time can and do you want to give and what not.

I use a 55 watt on my 20 long and I am happy with it that amount of light. It all depends on what you want to do and the time you have. IMO lower light tanks are easier to grow plants. Things are slower but allows you more time to react. It's a little more forgiving.

If I had to pick between the 2 options I would go with the 72 watts rather then the 90w total.

 

[farm41]

I have 256 watts on my 75g, co2 injection, loads of plants, algea eaters, dose fertilizer twice a week, trim once a week. If you want high light, you should be using pressurized co2, my 10lb bottle lasted 13 months last time, and I haven't had to mess with the co2 in years, it just keeps running smoothly.

Just like the last post, if you run out of co2, or miss fertilization a couple times, it can go to pot in a hurry.