# Photoperiod for a peculiar case



## erijnal (Apr 5, 2006)

I'm in the process of switching my 20 gallon from a high maintenance to a low maintenance set-up. The thing is, I'd prefer not to buy a new light fixture, so I'm sticking with my 65W CF fixture.

Has anyone tried doing a low-light tank with a higher wattage fixture? I'm trying to work around the problem by setting a shorter photoperiod, but I'm not sure what a good place to start is. I'd like to try and get it as close to perfect as possible because I've stocked the tank with a lot of crypts, and would like to avoid another episode of crypt melt due to a drastic change in photoperiod.

Some information: I plan on not fertilizing, and not injecting CO2. The fixture in question is using a bulb that is two years old, so the intensity isn't anywhere near what it used to be.

I've got three weeks to get this right before I go back to school, so time is a factor. Right now, I have my lights set to stay on for 7 hours.

Thoughts?


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## hoppycalif (Apr 7, 2005)

You have over 3 watts per gallon, and even with older bulbs you probably have the equivalent of over 2 watts per gallon. Neither is really a low light intensity. Reducing the time the light is on won't compensate for the high intensity either. You could raise the light about 6" above the top of the aquarium to reduce the intensity.

If you want to switch to no fertilizing, no CO2, you need to look into the el natural method. I don't think it is going to work otherwise.


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## erijnal (Apr 5, 2006)

I'm thinking about adding red root floater (Phyllanthus fluitans) to the tank in question. Would that be sufficient to cut down on the light intensity entering the tank?

The only thing I can't seem to find is how difficult the stuff is to get rid of. If the floating plant is the solution, I sure hope it isn't like duckweed.


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## cs_gardener (Apr 28, 2006)

I have to low maintenance/El Natural hybrid tanks that are 20 gallon talls with 65 watts CF and I only fuss with them every 2-4 weeks, cleaning the quick filter, trimming stem plants, or scraping a bit of GDA off the glass. I do have a soil underlayer that provides nutrients so no dosing of ferts. A couple times a week I dose Excel but I don't think it's absolutely necessary. So they are basically feed the fish and enjoy the tank. I do have floaters in both my 20 gallon tanks.

Red root floater is VERY easy to remove. Each individual plant is MUCH larger than duckweed and it also tends to stay connected in fairly large patches. You can easily scoop a bunch out with just your hand and it doesn't try to stay fused to your skin like duckweed and even Salvinia minima. Another easy-to-keep-controlled floater is Amazon frogbit. The roots do tend to get long on the older plants of Amazon frogbit so I just pick those plants out when thinning the herd.


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## MatPat (Mar 22, 2004)

If I were heading off to school and wouldn't be around to take care of my tank I would take the 
65w fixture off of the tank and replace it with either a single or dual bulb strip light or maybe even a 24" shop light. I have used 30w of light over a 10g tank low tech tank and even though I was around to fertilize and add Excel every day, I still had some algae issues. These were normal 15w strip lights too.

The Red Root Floater is easy to get rid of but with your light levels in a couple of weeks it will completely cover the top of the tank and may block out more light than you want it too.


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## HeyPK (Jan 23, 2004)

Crypts tend to melt in low maintenance tanks with high light, and the principal cause is the competition from other plants that are better adapted to growing in higher light and low CO2. The other plants will keep growing and the crypts will stop and appear to hold their own for perhaps several months, and then suddenly they will melt. When CO2 and nutrients are not kept up, crypts need to be in low light, not highly crowded, and by themselves.


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## erijnal (Apr 5, 2006)

So far so good. It's been more than a month and a half now, and I have zero algae, the crypts are growing steadily, and I couldn't be more happy.

The only plants I have in the tank are Christmas moss, a good number of Anubias, about 30 plants of various Crypts, and about 10 plants of E. tenellus. I'd classify the tank as lightly planted right now, but if the crypts keep growing, it'll be medium soon.


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