is 90 degrees to hot??

woodsmaneh! said:

The main reason you want to keep your plants below 85 is so they can maxamise the uptake of Co2. Above that and they stop processing it.

So 90 is to hot.

Why All Plants Need CO2


The dry matter in a plant is 90% carbon, hydrogen, and oxygen. All the
carbon has to come from the carbon dioxide (C02) in the air.
CO2 molecules are only necessary during the light times. Plants do not need CO2 in the dark period, and in fact plants breathe out CO2 all the time, just as humans do. The slight difference is that in the light period, leaves use up their own CO2 to make sugars and so appear to breathe out only oxygen in the daytime.
The more light available to a plant, the more CO2 it needs for photosynthesis. Experiments have shown that during photosynthesis, it takes about 1 a photons to make enough electrons to create sufficient energy to split one CO2 molecule into carbon (c) and oxygen (02) atoms and form a sugar. There are trillions of photons striking the plant leaves, so a grower must provide enough CO2 or else the photons will just bounce off the leaves without doing much.
A plant in full Sunlight (about 5,000 lumens per square foot) could process about 2,000 PPM of CO2 if it was made available in a greenhouse. Outdoor CO2 is nowhere near that. Indoor gardens with the light level at 3,000 lumens per square foot need about 1,500 PPM of CO2 for the limited light. With the level at 1,000 lumens per square foot, only about 300 PPM of CO2 is required - which is less than ambient air (city air normally has 400 PPM of CO2), The lower the CO2 level, the more the air has to be kept moving past the leaves.
Remember that it is the PAR value (not lumens) that indicates the plants' use of CO2 because the light that the leaves cannot sense is totally wasted and does not go down the photon funnel to be used for splitting CO2 into sugar.


Peace

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