light problem

[maddskillz]

i have a 30 gallon tank 2 c02 generators and 2 power compact lights 180 watts for both is this overkill because i have rainbow fish and there color goes away when the lights are on

 

[f250fisherman]

Thats 6 watts per gal. That is ok for some types of setups, but would be too much for some plants. 4 watts per gal will grow really well. At 6 watts per gal, it will not take long for the algae to overtake the tank. How long has the shark been in the tank? Normally a fish will get brighter colors when the lights are on, unless it is stressing. If it is new to the setup..it might take a few days for it to settle in. Does the shark have a cave of some sort to hide in? They love to own a shady spot in a tank.

 

[Colin_BC]

Trying to maintain a proper nutrient balance (N-P-K and more...) for the plants with lighting that high is going to be quite a pain. You're running 6WPG. I once had my lighting at 184W of compact fluorescents (DYI setup using 8x23W daylight spiral compact fluoro's) on my29G, and it resulted in tons and tons of algae growth. I had fast growing plants like limnophila in their, and it grew slower once I cranked my lights. All my plants became covered in algae, new growth only remained green for less than a week before being overcome with algae. My algae problem didn't subside until I cut the wattage down to around 4WPG. Once the wattage was reduced somewhat, everything in my tank started to grow much better (other than the algae).

I'd suggest sticking with one of those power compacts (assuming it's 90W) for now. I'd think 3WPG plus CO2 would still give some nice results. I'd worry that 180W total would grow algae quicker than anything, not to mention some fish really aren't fond of bright lights.

Colin

 

[Lateral Line]

I think he means Rainbows as in Atherinids, not a rainbow shark.

 

[maddskillz]

yep i ment rainbows and ye i have tons of alge i guess i am gonna cut back the light usage to one pc light at 90 whats thanks that clears up alot of ? i had

 

[Colin_BC]

I would test for phosphates as well. High phosphates can promote algae growth. I had a high phosphate problem shortly after the algae problem started. Once my lighting was reduced, the algae slowed completely and the phosphates have dropped.

Any existing algae in your tank will have to either be eaten by fish or removed by hand. In my case, I tossed out a lot of plants. Fortunately it was all stem plants. I simply snipped the tops off that were unaffected by algae and replanted them, discarding the remainder of the algae covered plants. I'm sure there are other ways, but my plants were pretty far gone at that point, plus I was lazy and knew the plants would grow back quickly anyways.

Colin