Slow growth rate in flowering

[Nickcorp187]

I think we might need to bring in the experts on this one. Here is my problem I am having slow growth rates in my flowering room. The plants stretch properly 100-200%, but when they stop stretching the buds do not properly fill in. This equals small yields and pisses me off. My grow room is 5x4.5 ft I have an oscolating fan blowing directly on the plants. I have a passive intake and a 500 cfm exhaust fan. The room is powered by 1000w hps and 2 100w cfls on the ground. Temps are 65-75 lights on and 55-65 lights off. Humidity is at 40%. Grow is done is a soilless mix of 1/3 peat moss 1/3 humus and manure and 1/3 vermiculite plus a 1/4 cup of blood and bone meal I also add lime to balance ph. I fertilize with bio bloom and top max in full strength from week 3 and 1/2-3/4 strength in week 1-3 of flowering. I used to grow in a 3x4ft closet and got bigger buds with less resin production now I am getting extreamly resinous plants but a much smaller yield. Check out the harvest pic below and you'll see what I mean. Any help on this would be great. Thanks NC.

 

[Nickcorp187]

Also I thought at first it was low light intensity which is what it looks like, but my garden is lit by a 1200 watts of light (1000w hps, 2 100w cfl) for a 22.5 sq ft room.

 

[Blackmelo]

how big is your pot?
Must be something you are doing differently if you used to yield more...

 

[Guest]

SOunds like your room is in order, Blackmelo asked it, but what size is the pot?

 

[lumbo]

I've got cool temps like yours in my grow in the winter and it doesn't seem to affect yield very much. Maybe a little. The cool temps keep the smell way down, though.

When's the last time you changed your hps bulb?

 

[Nickcorp187]

My pot size is 3 gallon.

 

[Nickcorp187]

I just changed my HPS bulb before flowering cycle 6 weeks ago.

 

[Nickcorp187]

Does anyone think because of the low temps maybe the water isn't evaporating in the pots because I noticed the soil stays wet on the bottom of the pot for over a week after watering.

 

[Verite]

Imo anything over 400 watts would benefit from supplimented c02. Growing with 1000 watts without co2 is just wasting light if the plants cant transpire without it.

 

[Guest]

have you changed strains?i noticed you said you used to get bigger buds with less resin and now it is the opposite.maybe whatever strain you're running now is just a lower yielder but a higher quality

 

[Blackmelo]

hmmm

 

[tricky]

i would try another strain is it sat or indica

 

[Nickcorp187]

I am growing several different strains mostly indica dominant.
Papaya(nirvana)
Northern Lights (female)
Wo town (local favorite) (columbian, thai, and skunk 1) (short flowering sativa)

I have grown both the Wo town and papaya in the closet and have gotten much larger yields and less resin production. Same light (1000w hps) smaller room. I don't get this at all. I'm stumped??

 

[Nickcorp187]

Thanks for the info JJ my ph is around 7.0 because I balance it with lime. Plus the plants I have in the veg room under the same mixture are getting extremely fast growth rates. My past grows have been in a soil mix of soil and vermiculite and/or perlite. Think maybe it could be the ballast for my light? I have ordered a new one because the wires inside my ballast are dry and starting to crack. The light doesn't seem as bright as it should be, but I could just be imagining it. Does anyone know if I could check the wattage output with a multimeter to make sure it is putting out more or less than 1000w or equal to 1000w?

 

[LavenderCowboy]

If grown from seed, what's the difference in vegg times between the two growrooms??? Did you add any dolomite lime or have any PH issues during the grow????LC

 

[Nickcorp187]

Imo anything over 400 watts would benefit from supplimented c02. Growing with 1000 watts without co2 is just wasting light if the plants cant transpire without it.

Thanks Verite but I used to supplement Co2, but good ventilation pulling in lots of fresh air is my way of doing it now. Does anyone else think I would benifit more from co2 injection or good ventilation? I would like everyones opinion on the subject.
Here is another pic from my garden

 

[Nickcorp187]

Thanks cowboy, plants were vegged for at least 4-6 weeks before the switch. I did use horticultural grade lime to balance my ph and haven't had any issues with ph. Do you think ph can contribute to such a small yield? I have never noticed any ph problems from the plants either extremely dark green no nute burn, no ph fluctuation.

 

[lumbo]

Hey JJ.

Hort. lime and powdered dolomite lime are different, I think. LC always said to use the dolomite, so that's what I use.

 

[Nickcorp187]

I have always used powdered horticultural grade lime to balance my ph in soil. It works like a charm. So do you guys think a heating pad under the pots will help the growth rate? Also it should help evaporate the bottom 1/3 of the pots because the top always dries out and the bottom never does. I'm at a loss here. I only have a few more seed plants I'm flowering out. I am starting to put in my DWC buckets for my clones. I figure the lower temps will really be good to keep a hydro res nice and cool. I am also going to replace the ballast in the next week or so. So I guess I will see if this change solves my problems. Hope so anyways.

 

[lumbo]

If the soil around the roots is routinely getting down in the '50s or low '60s, then I think adding some sort of supplemental heat is a good idea and will probably result in higher yields. JMO