How much light is too much light?

[bob112233]

Im wondering how much light is too much light for my120 gal tank. right now i have 4 floresent tubes with each tube producing 18000 to 20000 k. the tank used to be a coral tank i know it too much light but how much is right for my tank. as of now my tank is fresh water with about 20% plants, a nice chunk of driftwood and rest is sand. here is the stats from the last water test i did

gh/kh =4
Ph = 8.5
No2 = <0.3mb/l
nh3/nh2 = 0

 

[mr funktastic]

ask lonewolf how much it to much lol. how may watts is each light? u put the k rating but not the wattage. u can probably have alot more plants with that much lighting though so take advantage of it. u may also have major algea issues. but more plants will eat up the unsed light and u may have to look into co2. or just take out a bulb lol.

 

[Skyrmir]

If your fish are wearing sunglasses you might have too much light...

I dunno why but a whole series of Foxworthy jokes just ran through my head reading the question...

As funktastic said, the wattage is the real qualifier as to how much light you have. The K ratings you posted just show that the bulbs are set up for a reef tank. Can be great for showing color, but they probably don't put a lot of light out in the range of colors that plants use.

 

[bob112233]

each bulb is 40 watts. i did have more plants but they started to take over the tank all you could see was plants. then they started to get cought up in the filter so i took most of em out. i was hoping to take out some the coral and power grow bulbs and put in some normal floresent bulbs so i can keep the tank well lit but cut down on the algea and the plant growth

 

[Skyrmir]

40 watts on 4 bulbs is 160watts on a 120 gallon tank so your not pushing high light or even a need for co2. Most likely putting in normal bulbs instead of the coral bulbs would help the growth as well. If your having an issue with excess growth, it's probably the type of plants. Things like Anacharis grow at incredible rates. You might be happier with stuff like Crypts or anubias. They're generally low light plants, but even with better light they grow at a more managable speed.

 

[Wizzard~Of~Ozz]

40w bulbs, so they are T12.. You can pick up daylight deluxe or natural sunshine from Home Depot for 4-5$ a pair.. they are great for planted tanks.

And no, you don't have too much light. (I have the equivilent of about 280w T12 over a 75Gal.)