How many of you lower your lights vs fixed & dim

My instructions on my SE5000 lights say to lower them 24" over the plants, (would obviously dim as well in veg/early flower) but talking to Tim from Exotic Genetix, he says to leave them fixed above and just use the dimmer to achieve desired lights.
This is in a grow tent.

I have a smaller tent (3'x5'x 6'tall), I have 3x 225w LED lights.

When seeds have germinated, I start with the middle light only on, lowered and dimmed so that I'm in the 200ppfd-300ppdd range for the first week. As the plants grow bigger, I start un-dimming to keep good DLI for the week/period. Once plants are big enough to need more light and better spread, I turn on the two other lights in succession and start with them lowered and raise/adjust them to maintain a reasonable DLI for the week/growing period.

i use hangers and reposition. turning down the light makes the light at the bottom too little. that doesn't seem like a solid solution at all. i paid for a high quality high wattage light....i want to use what i bought.

I leave them up high, and use a par meter to adjust wattage.

bk78 said:

I leave them up high, and use a par meter to adjust wattage.

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Do you know what the par is supposed to be at each stage? I’d like to print out a chart

iggy097 said:

Do you know what the par is supposed to be at each stage? I’d like to print out a chart

Click to expand...

DLI is a good measurement to work with.

Daily light integral (DLI) is the amount of PAR received each day as a function of light intensity (instantaneous light: μmol·m-2·s-1) and duration (day). It is expressed as moles of light (mol) per square meter (m-2) per day (d-1), or: mol·m-2·d-1 (moles per day). The DLI concept is like a rain gauge.

This is the chart I follow:



And you don't have to calculate DLI by hand...there's DLI calculators available online.

Google a ppfd dli chart and it all fits on a sheet

bk78 said:

I leave them up high, and use a par meter to adjust wattage.

Click to expand...

I just did the readings on that in my tent. So for a veg par of 600 I’d need to have the lights on 100% if they are at the highest level in the tent.
so I guess if you’re trying to save electricity you would dim them and lower the lights

Heat and/or electrical costs come into play with a dim only option. I would prefer to only dim but find the need to move them a few times in veg. A nice way to deal with a dim only option is to platform them i.e. use a table in early veg, same as lowering the lights but easier on the back

I start/veg under fluorescent. These are kept within inches and moved up often. When they go to the tents with the big lights I don't move or dim, just let the plants grow into the light.