How often should I leave aquarium light on?

I have both plants and fish in my 5 gallon tank. Just a few anacharis along with a few neon tetras. The bulb is 25W. I really want the plants to grow so i can continue to replant.


-How long should the light be on?


-Does keeping the light on hurt the fish?





Also, I am in the process of putting up a 29 gallon planted tank. It will also have fish living with the plants. This tank will have more than just anacharis. Maybe a couple amazon sword/banana/java fern. Not sure yet.


-What wattage/type of bulb is good for this setup?


-How long should this light be on for?

How often should I leave aquarium light on?
8-12 hours maximum daily should be fine. any longer and you're going to find yourself with excessive algae problems.





as for wattage, the bigger the better, the watts per gallon rule is a good rough guide. for your plants which are low-medium light, aim for 2-3 watts per gallon, 5 watts per gallon would be optimum but you would have to be careful what fish you add as many fish don't appreciate very bright lights.





most fish stores stock bulbs intended for growing plants, aim for these for starters. as you progress in the planted tank world you can upgrade to more expensive specialist set ups.
Reply:well usualyy around 8-12 but if u really want to get them growing u could strech it out to 14 hours. most likely ur 29 wpuld be designed to come with thw long florescent tubes and ud want one designed for plant growth. 14 hours
Reply:The light needs to on for about 9 hour a day. for the 29g tank you will need likea 75w or 100w bulb to do better job.
Reply:i agree with the first poster....you'll know if you're leaving it on too long if you experience an algae overgrowth. Is your tank in an area where it gets natural light during the day? If so, cut back on the artificial light.

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