Good lighting for small tanks with light fixtures less than 36" have been a problem. Most fixtures less than 36" to be used with no flourescents are made with white plastic reflectors. I played around with the idea of using mylar to line my cheapo reflectors. I finally went to the LFS and bought a fixture with a polished aluminun reflector and 2 HO T5 bulbs for my 20 gallon tank. I was struck by the intensity of the light. Compared to my old NO flourescents with white fixtures. The light appeared to be 2-3 times as bright even though the wpg are virtually identical. No surprise, but it did get me thinking about how to determine how much light is actually reaching my plants.The type of bulb, quality of the reflector, distance of the light from the water, cleanliness of the tank top etc. all affect the amount of light.
I like to keep small tanks in the 20 - 30 gallon range with diy co2 and 2 -2.5 wpg. I normally use 3 liters of wine yeast and sugar per 20 gallons and that seems to provide a reasonable and steady level of co2. I do EI dosing "by the book". Will my HO T5 lights of 48 watts on a 20 gallon be too much light ? Does WPG have any real meaning ?
I also have been looking at power filters and co2 loss. I always "over filter" my tanks. I use an aqua clear power filter rated for a 50 gallon tank on the 20 gallon described above. The normal recommendation is to keep water levels high to reduce co2 loss. To be honest, it appeared to me that keeping water levels very high in a tank with a larger power filter pushes the water down and forward. The forward motion causes noticable ripples. When I lowered the water level the water falls into the tank with less forward motion and surface turbulence seems less. It also appeared that for tanks larger than 20 gallons you really need to add a power head to get decent circulation if using a power filter. I don't want to mess around with a canister filter for a small tank. Maybe I'll stick a sponge on a power head. I use a drop checker, but there appears to be something wrong with it. It always measures the same level of co2 in all my tanks so I don't have any real objective data to support my obsernations.
Henry
I like to keep small tanks in the 20 - 30 gallon range with diy co2 and 2 -2.5 wpg. I normally use 3 liters of wine yeast and sugar per 20 gallons and that seems to provide a reasonable and steady level of co2. I do EI dosing "by the book". Will my HO T5 lights of 48 watts on a 20 gallon be too much light ? Does WPG have any real meaning ?
I also have been looking at power filters and co2 loss. I always "over filter" my tanks. I use an aqua clear power filter rated for a 50 gallon tank on the 20 gallon described above. The normal recommendation is to keep water levels high to reduce co2 loss. To be honest, it appeared to me that keeping water levels very high in a tank with a larger power filter pushes the water down and forward. The forward motion causes noticable ripples. When I lowered the water level the water falls into the tank with less forward motion and surface turbulence seems less. It also appeared that for tanks larger than 20 gallons you really need to add a power head to get decent circulation if using a power filter. I don't want to mess around with a canister filter for a small tank. Maybe I'll stick a sponge on a power head. I use a drop checker, but there appears to be something wrong with it. It always measures the same level of co2 in all my tanks so I don't have any real objective data to support my obsernations.
Henry