Does in sump LR need light?

[swissfish]

If the answer is yes, how much?

[mattmku]

the purpose of live rock in a sump is for bacteria for the nitrogen cycle. These organism need no light to survive.

[swissfish]

thank you, thats what I thought but wanted to make sure.
I'm terrible in chemistry

[BillyZ]

mattmku is right on the bacteria. A lot folks will also put algaes in their sumps for additional nutrient export. These, obviously, would need some light. But you could easily get away with a simple 20watt NO fixture.

[dralarms]

What I did was to put my lights on a timer opposite my tank lights, I may not need it in my sump/ref. but it keeps my o2 level even. I was told once that your o2 level drops like a rock when you turn out the lights so I put the light in. I have 2 40 watt "grow" lights for my sump.

[foma2000]

i have lots of lights on my sump. i figure the more plant life, the more oxygen. i like the idea of oposing the light cycle to keep o2 levels even. thats really cool

[dralarms]

i like the idea of oposing the light cycle to keep o2 levels even. thats really cool

I heard it here first.

[swissfish]

Sorry guys, me and chemistry

What has light to do with o2?

[foma2000]

when the plants are well lit the plants take in co2 and put out o2. during the night they stop producing o2 and even release a small amount of co2. therefor, durring the night (or when the plants arn't lit) there is a large drop in o2 levels.

[swissfish]

when the plants are well lit the plants take in co2 and put out o2. during the night they stop producing o2 and even release a small amount of co2.

Thanks, can I have some more Info?
Plants on the live rock? Algea?

Looks like I faild my Biology class too

[foma2000]

all plants including algea and the stuff on the live rock. the idea of switching the light cycles on the sump and the tank is to make shure that there is always some oxygen being produced in the tank even when the lights in the tank are off

[swissfish]

thanks guys for your help.

And if you have the the sump lights on at night you'll save money because electricity is cheaper at night.

[dralarms]

because electricity is cheaper at night.

Not aroun d here.

[BillyZ]

the other benefit to maintaining constant O2 levels are that the amount of O2 in the water also affects teh Ph level of the water. constant O2 = constant Ph. You can see this for yourself by simply testing the Ph levels through out the day. test it in the morning before the lights come on, test it mid day and then again just before the lights will go off. you'll quite likely get 3 different readings.