Lighting Advice

Themuleous

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I found this while trying to work out what I'm doing wrong and thought it might be of use to some people on here. I will be trying this on my 20g tank. The writer is a Dutchman who is a specialist in plant physiology and by all accounts knows what he's talking about. Its certainly worth a try.

Sam

Understanding fertilization is very complex.

1) High light tanks - like yours- are reacting different than low light tanks.
To be short on this one : The need for higher NO3 and PO4 concentrations is a direct result of the high light + CO2. You can say the plants need a sort of overpressure of these macro's during the high light period. The growing speed is at maximum and the internal buffer of the plants will only last for an hour or so. After that point the macro's in the water will be the supplier.
That's the reason why higher concentrations work out better in high-light tanks.
It's a bit strange that a high light tank doesn't do well with say 3 mg NO3, isn't it?
After all, there is NO3 available !
The overpressure makes it easy for a plant to get enough NO3 at the peak.

2) The micro's are very necessary of course. The whole chain ( macro's and micro's) has to be complete for optimal assimilation.
But, there is not a need for an overpressure of the micro's. They are taken active by the plant : they have certain receptors for uptake.

Too much micro's can lead to algae. Especially in non-mature tanks. The bacterial stability is not optimal and the plants are just shooting roots and a few small leaves.

In my opinion it's better to calculate the biomass and dose according to it.
If you put all your plants in one place... how much space will they take?
Perhaps 1/4 of the space?
So we need to dose micro's for these plants and 1/3 should be ok to start with during the beginning ( say 4 - 6 weeks ).

3) the peak with the lights has several advantages.

2 lamps ( 108 Watt ) = low light
This will allow the plants to grow steady and easy. In fact under these low lights the plants can do with lower NO3/PO4 because everything is easy running.

4 lamps ( 208 Watt) or more lamps = high light.
Now the plants need to have more NO3/PO4 etc and running low on there internal buffer. The overpressure of NO3/PO4 helps them out.

This high light period for 3 -4 hours is enough to keep the plants down and give them enough impulse to grow nicely with red leaves ( if they can)

A big advantage is that you can play with the growing speed of the plants by adjusting the total high light hours. 3 hours is normal and 6 hours high light means turbo-boost. But also more worries if there are enough macro's available.

A smaller peak ( say 3 hours) will not punish you hard when you're forgot to dose macro's or running too low for some reason. It forgives you to a certain point.
Isn't that nice?

Gr.PJAN
Right the lights.
Sorry if I made a mistake or so in my poor English.
The low light period is "easy growth"
The high light period is " turbo growth".

The hours of high light is very important. This period will get the plants to grow fast, give them color etc.

You start out with 3 - 3 - 3 hours. The middle period is always high light.
3-3-3
low-high-low

After 4 weeks :

3-4-3

Most of the time the last schedule will satisfy you. But in the beginning you're not going to push the plants to the max and only use 3 hours period of high light.
It's a bit of experience and also depends of plant species.
If you have only ferns... the schedule will be :

4-2-4

If you have more fast growing or demanding plants, the schedule is a bit higher :

3-4-3

or if you want to have a huge amount of plants and like pruning :

3 - 5 - 2

The longer the high light period, the higher the levels of NO3 and PO4 must be. Too long period of high light in a non matured tank, will give algae.
So in the beginning you have a rather short period of high light, just to keep the plants and the boss happy. The biomass ( plants and bacteria) must develop a balance and that takes some time. Normally a week or 6.

To be very clear on this one : the high light period is to keep the plants down and red if they can. The low light period is to keep the plants just growing with no need for speed.
For dummies :
low light = keep the boss happy ( less algae)
high light = keep the plants happy

Pfff.
 
I like the way he describes the principles of luxury uptake etc. using terms like overpressure.

What site is this from Sam?
 
Very interesting read. I often wondered why plants grew better with 20ppm plus NO3 rather than 5ppm. Often thought about doing the bright midday light period but never got round to it. I will try it some time just to see if it makes much difference.

Thanks for posting Sam

James
 
Enlightening isn't it? And although English isn't his first language he explains is in a clear and easy to understand way.

Sam
 
Briefly looking through the ADA catalogue, a lot of the people on there run their tanks with NO3 at <1ppm. I guess the substrates they use compensates for this. Any thoughts?

Dave.
 
As far as I know, thats exactly what happens. The aquasoil provides lots of the nutrients. If you've seen any of the journals that have used it this is probably why/a result of the HN3 it seems to contain/cause.

Sam
 

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