hey thc thanks for stopping by
appolonio - probably beginners luck but i grew this cross out before and was very pleased with it, which is why im going to the next level and making f2's
hey MB - i hope my calculations meet with your approval
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right, the yields and analysis on the previous run.
Powerplant yield was 54 grams, which divided by the actual power usage for the quarter,180/4 = 45w, works out as 1.2 gpw
Northern lights yield was 46 grams, which i will round down to 1gpw
and the Blueberry was 44g which i will round up to 1gpw
for the comparison to my 250 i wanted to give a true watt for watt analysis, and we all know that a 250 uses more that 250w so i bought a power meter to test my hps (magnetic ballast) and after half an hour on it read 302w, but lets call it 300w as a nice round figure, which gives a power usage of 75w per quarter for the hps. (please also note i have a very good reflector for my hps too, an ecotechnics diamond which are rated about the best on the market in the uk for the anount of light they reflect)
i went back and recalculated my gpw for hps yields based on the real power usage which is only fair in a proper comparison.
the
power plant real gpw under my hps was 1.05 (as compared to 1.2gpw if you use the 250 figure - so you can see how these calculations often flatter hps for yield)
so for Powerplant, LED = 1.2 gpw, HPS = 1.05gpw which shows that watt for watt actually used, the LED yielded 14.5% more
for the Northern lights, i have used a grams per watt per month calculation because the yield data i have are for different flowering periods between 8 and 10 weeks
for LED we got 1gpw which for an 8 week flower equates to
0.5 grams per watt per month for LED
and for hps i have 3 figures for NL which equate to 0.53, 0.416 and 0.416 gpw/month so we take an average of
0.45 gpw/month for HPS
so NL, watt for watt, LED yielded 11% more than HPS per month
lastly the Blueberry i will use gpw/month again for the same reason.
the LED gave 0.4 gpw/month (10 week flower) and the
HPS gave 0.33 gpw/month
so for the Blueberry the LED, watt for watt, yielded 20% more per month
gonna post this now before i lose it
other things i should mention are that the Bb and NL were affected by mites during flower which will have reduced the yields a little in this LED grow. the Powerplant was largely untouched. the Blueberry also got a setback when i sprayed with neem and it burnt the hairs early in flowering - but it bounced back.
in terms of total yield for the cabinet the '250' HPS would beat the '205w' LED, but you need to consider that the 250 hps ACTUALLY uses 66% MORE electricity than the LED unit - which to put it into perspective is more than the difference between a 250 HPS and a 400 HPS
VG
so will you keep using led or go back to hps?