I have no meter, but I’ll download an app sometime, to check it out. It’s not quite as bright as it looks in real life, to my eyes. There does though seem to be a problem. I connected up the thermostat and it shows that it’s 30c with the lighting on. The thermostat probe wasn’t in a pot or anything, so it might just be radiated heat acting on the probe, I don’t know. Thanks for the info on tomatoes, I’ll keep an eye on it, when the time comes
Before I got a light meter, I had my big Envirogro T5 fitting too low, causing it to get too hot (and bright) underneath, as a temporary solution, until I raised the lights and fitted an extract fan, I put the propagators on a timer so they were off when the lights were on. Your lights appear to be even more powerful than mine. P.S. My cheapo LED tubes finally go live today.
I've placed 2 propagator sized gravel trays [1] on a desk in my study by the window with the 4 tubes above fixed to a sheet of plywood and resting on timber rails so it can slide across from one tray to another, probably every 12 hours. I get a reading of 11,000 LUX 225mm beneath the tubes where I now have my onions, leeks and sweet peas. Without the lights I get only 3,000 LUX from light coming through the window. N.B. no mylar surrounds have been added yet. My plan is to use them initially for plants where I want to reduce heat after germination when indoors, or possibly use over a heated propagator if somewhere like an unheated shed or greenhouse. No idea how plants will 'like' the light from them, but I do have a 60 watt LED blue/red light to supplement them, and as all my boxes are built to suit the same size propagators/gravel trays [1] , they can be swopped around. I already have 174 pots and modules of various sizes full of seeds, seedlings and plants in my study, and as more and more get pricked out the need to put my greehouse heating and growbox on gets ever closer, but £25 on a week's heating fuel in freezing weather is gone forever, and £25's worth of LED lighting will last for many years. And they may be suitable for the likes of bringing on early lettuces after the initial plants have beern moved on. If this setup works OK, I might go for more 4 tube panels, stacked on top of one another in the window, up to 3 tiers high, holding a max of fifteen 24x cell trays (360 modules). [1] My propagators and gravel trays are all approx. 15 x 23", for example they will hold two and a half 24x cell trays, 60 of those modules each. This really does help with shifting whole trays of pots/ modules in trays around about twice a day to get the most use from lights.
11,000, sounds pretty good, based on your earlier posts. How is the heat from the tubes? I might have to consider doing something similar, as heat seems to be a real problem for me. Out of interest, I put a thermometer inside the box, in shade. It read roughly 21c, so I got the idea to shade the growing area. Oh, hang on... The fan and speed controller turned up today. Only one problem, the plug for the power source is a small 3 pin affair, and according to the spec, requires 12 volts. It looks like the sort of thing that gets plugged into a motherboard. Any chance of a piccy of your latest setup?
As mentioned above, any old 'mobile phone' charger, or AC to DC adapter will work. If the fan requires 12v, then 9v or 6v will also work but it will just spin a bit slower, no problem as that means a little less throttling down using the speed controller. Do you want me to post pics/details of the connections, colours of cables, etc.? You will require some small connector strip. P.S. Heat from the LED tubes is virtually non existant.
Oh, I installed a lux meter on my iPad. At the centre of the box, I’m reading around 20,000, and around 15,000 at the ends. It’s a bit hit and miss though, as the level isn’t recorded, so I have to tip up the screen to be able to read it.
I didn’t notice at first, there’s a facility to flip the screen. I’m getting some very variable readings. Over 100,000 in the centre! I don’t think it can be trusted...
@Scrungee , don’t worry about the wiring thing, found this... USB A Male to 3 Pin Case Fan Adapter Connector Cable: Amazon.co.uk: Electronics
I’m looking at this... Lux Meter GrandBeing Handheld LCD Light Meter: Amazon.co.uk: Electronics @ARMANDII , as good as any, for the money?
Sorry, Freddy, I'm not always sitting in front of the Steam Machine so it wasn't until I came in out of the Kitchen that I came across your post. Well, Lux is a good brand and is rated but Light Meters are a bit of mix when it comes to accuracy. I got several Light Meter of good quality but have found that I can get two different readings from two side by side meters. Obviously, you want to keep costs down but I would think that it might serve your purpose in giving you how much candle power your lights are producing in the box so as you're not looking for the exact measurement it should be okay.
