# Low light and submersed growth



## HeyPK (Jan 23, 2004)

This is an old Ektachrome picture taken in 1967. I had three fifteen gallon tanks and I laid a single 40 watt T-12 fluorescent tube across them. That gives each tank exposure to about 12 inches of the tube. That is about half of the light the tank would get if you put a single 20 watt tube lengthwise along the tank. So, these tanks had less than one watt per gallon, but the growth of the plants looks pretty good. From left to right: C. beckettii, C. cordata, and C. crispatula.


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## EDGE (Feb 28, 2004)

I always thought crispatula needs a lot of light to flourish, but this proves that it can still look tall and green with minimal lighting. Do you remember if you dose anything to the tank?


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## HeyPK (Jan 23, 2004)

In those days I never even thought of having more than one fluorescent bulb over a tank., and, actually, I had quite good growth with all the crypts I could get my hands on, which wasn't that many species. 

I was dosing with small amounts of a macronutrient solution that had KNO3, Ca(NO3)2, MgSO4, and KH2PO4.


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## Plattykins (Apr 3, 2005)

Some time back, I increased my light from a single 8w tube over a 10 gallon to two 8w's. One is a Sun-glo and the other is an Aqua-glo. I made simliar adjustments to my other tanks. This bit of wattage seems to be adequate to produce healthy crypts, especially when a typical liquid fert w/iron supplement is added on a weekly basis, which increases the growth rate. I get good color and healthy leaves and roots. I have a variety of grass and stem plants as well, but the crypts do the best, being low light type plants. Egeria and some medium-light stem plants do ok. Heck, even the Amazon Swords to well, which came as a surprise to me.


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## HeyPK (Jan 23, 2004)

By "this bit of wattage", you mean 16 watts, right? I wouldn't be surprised if the crypts did well with 8 watts. I really like to start tanks off on quite low light and increase when the plants are well established, and green water is not going to be a problem. I also find that Amazon swords do quite well on low light. I have a 20 long tank that has five or six of the big old "tank buster" swords doing fine with two feeble, old, T-12, 20 watt fluorescent tubes.


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## Plattykins (Apr 3, 2005)

We're talkin' 16 watts over a 10 gallon... only 1.6 watts per gallon. Around a watt per gallon on the larger tanks. I see your point overall though.


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## defdac (May 10, 2004)

HeyPK said:


> I was dosing with small amounts of a macronutrient solution that had KNO3, Ca(NO3)2, MgSO4, and KH2PO4.


Wow, already back in 1967? You must have smiled when folks started invent names for it like PMDD? =)


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