what this mean?

[netobeto]

what does K mean on the lighting for the tank the one i bought today its said it 18,000K but it was only 15 wats so its that good for my 28 gallon tank? or should i change it for another one to keep plants alive?

 

[bigmick474]

i dont know what the k is but i think u need a haight watt light to keep ur plants alive.
15 watts give u just over 0.5 wpg which is VERY low, not many plants can survive with such low light

 

[netobeto]

could you tell me which one would be alright for the 28 gallon tank?

 

[Silly me]

you would be looking at 5500K - 6700K at about 60+ Watts for plants..

28G tanks are normaly 3 foot long so 3x 25W 3foot tubes should give you 2.6wpg

well thats the min I would use.