Betta_dude

Im starting to put plants in my 38g. How many watts do I need. My book says 60 watts for every 15in. of depth.

mathas

Different plants need different amounts of light, so the answer to your question will depend on what type of plants you want to add.

Do you know yet which plants you're looking at?

soldieroffortune1974

For a 38 gallon planted aquarium,you need 76 watts of light (2watts/gallon) that's minimal even for low-light plants.Or you will get an increase in diatomes (brown algae) due to the extra nutrient requirements for the plants. Meaning higher phosphates for the algae to feed on,and not enough light for the plants to utilise the extra nutrients.

mathas

I would have to disagree that 2WPG is minimal for low-light plants... that's probably more in the medium range, not the low end of low.

Of course it would be nice to have that much, but it's not needed.

GreenMan13

I agree.

Betta_dude

Well looks like I need a new bulb. Min is only 17w.

soldieroffortune1974

You are correct,assuming ALL the plants in the aquarium are "low-'level" plants. You need to take into consideration,the plant that needs the most light,and use that as the basis to determine 'low-level',or some plants may thrive,while others die off. That was my theory of 2 watts/gallon.Most plants do well at that range,that's why the general recommendation for planted aquaria is 2 WPG.

GreenMan13

That's why that would be the medium range not the low end. Same with everything, most things do best in the middle of the range, natural Gaussian distribution.

Betta_dude

Thanks, Ill keep the 2wpg in mind. All I have so far is java moss,water wisteria, and amazon sword.