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Ever heard of a 600w MH bulb giving serious problems to plants before?

H

Hosttrevor

Member
Hi, has anyone heard of any 600w Metal Halide bulbs that seriously hurt plants? I don't mean from being too close and giving heat stress.

Sounds odd I know, but I think I have one that really messes with the plants.

I've been fighting off gassing, then thought maybe broad mites because of the glossy blistered affect of the leaves and new growth stunted and deformed.

I had 16 clones in 4" pots sat 24" under a 600w MH bulb. The plants quickly started to die and I realised they were suffering from off gassing as I was drawing air from the house which has recently laid and glued down carpets and lino. Its something I've had to deal with for a couple of years sometime ago. So I sealed the room up and vented fresh air from outdoors and exhausted out too. Things improved to the extent that the ill affects arrested, but come back was incredibly slow, really stunted with long gaps between internodes and the stems all purple. As they grew slowly I potted up into 6" pots and spread them out under 2 MH bulbs (different manufacturers). You could see a very clear difference in the colour of the bulbs, despite both being MH 600w.

It took a while, but I noticed the plants under the new light looked to improve, lost their glossy blistered look and started producing normal looking healthy growth. It took a while to see this as the plants were very sickly.

So I switched one of the good plants with one of the bad plants and low and behold the good one gets worse and the bad one improved. By now you could see a clear line through the grow where the 8 plants were healthier and growing better on the left and the 8 on the right continued to look horribly glossy, although better than they were before the air circulation set up was in place. The off gassing is I think cured, but the light is seriously inhibiting the 8 plants under it.

Has anyone come across this before? It seems so strange, but is very apparent.

I suspected Broad Mites for a while, as the symptoms were so similar to that of a very heavy infestation, but after using a USB microscope to scan badly affected leaves and new stunted growth, not an egg or mite to be found, phew! They sound awful to deal with, unless you don't mind poisoning the smokers of your produce with chemical miticides. Anyway, mo BM's in my grow thank goodness.

I'll post some pics of the plants a little later today to show the struggle the plants have had, and the comparison pics as they are under now. Well until half an hour ago, I've now replaced the suspect MH bulb with a sodium halide. I expect things to get better now. . . . lets see.

The suspect bulb is a Trilite 600w MH

Anyone with experience with this?

Thanks, Trev :tiphat:
 
H

Hosttrevor

Member
some pics showing the difference

some pics showing the difference

Here are a few pics showing the difference between the plants under one light to those under the other.

I did notice that the offending light was much whiter than the other MH bulb, almost making the other one have a yellowish appearance. I've now replaced the suspect light with a 600w HPS. Are there different spectrum MH bulbs, and are there any that are useless for a growers needs?

These are the 8 plants recovering from off gassing that were under the suspect light, notice the high gloss look to them and small thin leaves



And here are the ones under the other light, notice fuller leaves and the only glossyness is on old lower growth, the upper growth appearing normal again



As you can see there is a clear difference with a distinct halfway border between the 2 groups of plants/lights.

All the plants were under the offending bulb for weeks until I spread them out after slow growth eventually dictated that I split them between the 2 lights. Its taken til now for the difference to become very apparent. I swapped one plant from each and they started changing, the good one moved to the bad area worsened and the bad one moved to the good area improved.

I'm certain its not localised off gassing, as this room is sealed pretty well from the newly glued down carpets and lino that's throughout the rest of the house, and I have excellent circulation blowing fresh air around both sets of plants and excellent air transference.

It so obviously points to the light, but I've never come across or heard of anything like this happening before. I'm glad I had a different manufacturer's MH bulb for the second light, otherwise I'd have had two of these bulbs over them and continually chasing phantom symptoms and off gassing.

Here's one where you can see the two groups of plants where they reside in the room, the good plants on the left, the ones still struggling on the right. I hope now I've removed this suspect bulb from the grow I'm hoping to see things improve in the 8 plants that are lagging behind.



You can see the room is sealed with Black and White plastic and battoned tp the wall and every edge or seam is taped up with heating engineer's foil tape, stands the heat and humidity, unlike gaffa tape. One wall between this room and the carpeted house is tongue and grooved wooden partitiion, so I've also foil taped every join between the wood where they join up and there is no gas coming through there.

My large extractor fan is in a box filled with expanding foam, a serious off gasser, but I have it wrapped and sealed with black and white plastic and it is right next to the extraction filter so any poisons should be pretty much exhausted out of the room. I am going to wrap it in a couple more layers of black and white plastic and tape it all up, just to be extra cautious.

Has anybody experienced this? As you can see from the photos there's definitely something to it, can you figure it out or offer any possible explanations. . . it seems so weird!

The tops of a plant from the good group



The tops of a plant from the bad group, not the best example, but you can clearly see some of the glossyness on the top growth.



I hope someone can make a response here cos I find it totally baffling.

Thanks, Trev
 
H

Hosttrevor

Member
Here's what the plants looked like 2-3 weeks ago









So they're improving well enough after a very slow recovery, I'm hoping the ones that were under the dodgy light will soon catch up and loose their sickly look.

Any info on this would be greatly appreciated.

Thanks, Trev :tiphat:
 
IslandGrown

IslandGrown

Member
Metal Halide lights often give off a different light spectrum than high pressure sodium lamps. Most people use MH for veg and HPS for flowering but the tops of your plants look super dry. Is your light too close? Also purpling off plants could be because of a non stable temperature...maybe too cold? Sorry if i didnt help!
 
furrywall11

furrywall11

Member
Hey, I had a large greenhouse that I was supplementing with 600 watt metal halide bulbs and 1 600 watt HPS bulb. One morning I came in and it looked like my plants under the MH bulbs had all gone purple and the plants under the HPS didn't....the purple turned almost black...and then faded to that rusty color you see on yours. They were also kind of deformed and twisty. The plants under the HPS were barely affected. At the time I theorized it was lack of ventilation in the greenhouse. Some kind of buildup of gasses from the burning of the high intensity lighting. I lifted the lights some and opened one end of the greenhouse completely... The plants didn't get any worse but they didn't get much better either. It was a very odd phenomenon..something that happened almost over night. Eventually, I forced them to flower with 12/12 natural lighting -- the yield was reduced. I don't know for sure that it was the MH bulbs your post got me to thinking about it.
 
H

Hosttrevor

Member
IslandGrown said:
Metal Halide lights often give off a different light spectrum than high pressure sodium lamps. Most people use MH for veg and HPS for flowering but the tops of your plants look super dry. Is your light too close? Also purpling off plants could be because of a non stable temperature...maybe too cold? Sorry if i didnt help!
Click to expand...

Yeah, thanks mate, I know the tech behind the bulbs, I been growing 25 yrs now, but I appreciate your effort.

This particular bulb made my other MH look almost yellow. Now I've replaced the suspect light with a HPS, the good MH looks just right in its coolness along side the HPS. Just the suspect one looked whiter than white, to use a washing detergent's advertising phrase.

Lights are 24" above the top of the plants.

Actually I have had fluctuating temps due to weather changes and the outdoor air that supplies the room with fresh air and it was cold for a spell, but not of late.

I definitely had off gassing that affected all of these plants badly and evenly, ie. every plant the same damage. I installed a good outdoor air source for them and plenty of it 990m3 rated fan, then kept them under the dodgy MH bulb for 2-s weeks, maybe longer, they've been so slow in growth. Its only since adding the second MH bulb that I've noticed a very marked difference between the improvement of the plants that are under this second light in comparison with the others that remained under the suspect bulb.

It all sounds a bit f*cked up to me, but that is what the evidence reveals.

I think I've solved the off gassing issues i my room, but maybe I still have something off gassing in their, and I'm going through everything and double sealing anything I consider to be of risk, but this wouldn't explain why some are failing to recover the same as the ones under the next light?

Trilite 600w MH. . . . . anyone using these?

Can bulbs be faulty from new and give off a bad spectrfum? I'd have thought the plants would just not thrive under it if so, not have all this glossy growth.

I'm totally confused by this, and hoping someone with expert lighting knowledge would be able to straighten out the confusion, but I've searched the internet and I just can't find anything relating to this issue, other than what Furrywall had to say. Interesting Furry, did you ever try using the bulb again, or remember the make of the bulb?

Thanks, Trev
 
H

Hosttrevor

Member
The side by side pics above, both sets of 8 plants have a 600w MH over them. You can see the colour difference to some extent between the bulbs in the photo.

Trev
 
furrywall11

furrywall11

Member
I'm curious about what causes glossy leaves. There are many different causes of brown or taco leaves that you can find all over the net but glossy leaves is a little more unusual....maybe that could shed some light on this. I can't remember what bulbs I used but they weren't an off brand.
 
H

Hosttrevor

Member
furrywall11 said:
I'm curious about what causes glossy leaves. There are many different causes of brown or taco leaves that you can find all over the net but glossy leaves is a little more unusual....maybe that could shed some light on this. I can't remember what bulbs I used but they weren't an off brand.
Click to expand...

Thanks, I agree about the glossy leaves thing, I can't find anything out about it and I'm more than curious mate ;-)

Trev
 
H

Hosttrevor

Member
Gelado` said:
I looked up Trilite and their bulbs are made in Zhejiang, China. I've heard of Chinese HPS bulbs causing problems before, so maybe it's the cheap Chinese halides too. Moral of the story...don't buy cheap bulbs! Zhejiang-made halides go for as little as $2.50 USD (retail) in China. After looking at your pics, $25-30 for a decent bulb sounds well worth it!

http://cntriumph.en.alibaba.com/pro...302/MH_600W_grow_lighting_for_hydroponic.html
Click to expand...

Interesting perspective, and with some of the rubbish that comes out of China, I wouldn't be too surprised. I'd be more convinced if I heard of other people having similar problems with them. There must be shitloads of them out there in use as they're on sale on ebay.

I was on a very tight budget when purchasing, but MH is MH, and I though the worse that could happen form a dodgy bulb would be poor growth, not rich and highly glossy leaves and stunted growth.

I'd be interested to know if there's anyone out there who's used this Trilite MH bulb with good or bad effects in the plants.

Thanks for your angle mate ;-)

Trev
 
Some old dude

Some old dude

Member
Wild

Wild

Wild ..I never seen a bulb do this type of damage...I usually buy the cheap 400 w MH for mothers but still I pay around $ 40-50. Always use hort eye for flower . :tumbleweed:
 
ozzieAI

ozzieAI

Well-known member
Veteran
i was under the impression that glossy leaves manifest when a plant wants to protect itself so the theory of high uv seems credible given the evidence provided. cheap lights generally prove to be a false economy...go for quality every time...

good luck
 
H

Hosttrevor

Member
Tonygreen said:
I bet yer bulb was bad and emitting crazy uvb light which kills plants.
Click to expand...

Is this a known phenomenon Tony?

I can see it could bear out, but I've never heard of these problems before. Stupid, I cheaped out on the MH bulbs, but bought top of the range flowering HPS's

Trev
 
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