Burning with 150 W MH ?

[fhydro]

Hello,
to enhance my 250 W HPS lighting during veg, i added a remade 150 W MH very cold light. But, i noticed that the leaves after a few hours begin to burn a little on the sides. There is a glass board on the lamp to prevent from UV rays. I put a dome to protect my AK47 seedlings. Who knows what in the spectrum can hurt plants ? UV rays ? Or am i mistaken.
Fhydro

[HARDDON]

UV rays is another one of those debatable issues.

The sun bombards outdoor plants with UV rays, so, whats to say anything is wrong with them?

If I were you, I Would...

1. Remove the dome. What are you protecting them from? Remove the threat.
2. Get a fan on those blowing across the seedling tops right now. You'll thank yourself later.

A little circulation in the set up will do wonders for your grow.

Domes are good for clones for a bit....but just not needed for seedlings.

Get them expose to the environment now.

Lose the dome... :)

[fhydro]

Thanks Harddon, but i meant "too much UV" maybe more than the sun, because what i noticed is true. Growing is faster with that 150 W MH than with my 250 W HPS, but the leaves begin to twist on the sides, like drying, strange. I've got a fan, must it blow 24/7, mine is blowing 15 minutes every hour...
Fhydro

[HARDDON]

BLOW 24/7...

Sounds too hot. Keep the hot air OFF of them. BLOW across the tops all day and night....it makes for stronger plants, stems and branches.

UV isnt the problem....

[fhydro]

I put off the dome and put the babies AK47 and sensi skunk ( 4 days ) in a little bubbler expecting for new buckets to put them one by one. I bought a MH conversion bulb, so i've got 250 + 150 W of MH. OK, that's better. But, Harddon, look at the close ups, look at the edges of the leaves, little twisted, it appear as soon ( few hours ) as i put the MH bulb. BUT, i will blow the fan 24/7, you convinced me.
Fhydro

[HARDDON]

shit dude thats a hell of a setup you got going.

I had no idea it was a soil-less grow.

Perhaps someone more familiar with this setup could help.

The leaves you are referring to look ok to me. Looks as they are just turning up to grab the light, nothing more nothing less.

But again, I am not a bubbler knower.....you need to ask Zandor about this issue to get a real pro's advice.

I still say stay with the fan 24/7... what is the air temp at the plant surface?

[fhydro]

Thanks! The temp is 25 celsius at the plant level in front of the fan. I saw that the MH is better (in a few hours) than the HPS to veg. I will keep you aware...
Fhydro

[latewood]

Nice neat setup fhydro......hey dudes, I grow with similar setup. I believe you only needed to run that oscillating fan 24/7...not just for heat, but it strengthens the plant tremendously...I agree w/HARDDON...uncover seedlings,which you did...I run 400MH along with 250hps and the opposite rection occurred with mine?...I started with fluoros/seedlings...then 400MH, because 250hps had not arrived...when I hooked it up
30" above canopy, my darlin's freaked out...my 3 of 5 soil went nitrogen deficient, one perked up hard...some of my hydro(12) started to look waxy and some twisted, some
had slightly curled leaves...I raised the 250 hps a little above the MH to just supplement the 400MH ((they were thriving under just the MH), also MH is said to be better during veg phase with the hps being preferable during bloom phase))together is even better with a 60/40% MH/hps ratio)))...that was 10 days ago...most recovered
fine. I decided to weed out 4 week hydro's by flowering them...I actually have the 2 different lights so I can have a veg room and a flower room, and I might add that the fluoro IMHO is the way to go the 1st week-10 days...IMHO..latewood

[fhydro]

Hello, now that i blow the fan 24/7, the temp at the plant level is 23 celsius. It's a little coldy no ? People say to maintain temp at 26-27. Should i stop the fan from time to time ? Anyway, the plants seem to like the new MH bulb.
Fhydro

[Zandor]

Once you get the first set of true leaves you no longer need the dome. The idea of the dome for seedlings and clones is to raise the RH level above normal so the light will not burn the leaf from the inside out. I.E. dry out the leaf.

I quit using domes for clones a few years ago I found that the anti-wilt spray works so much better then a dome. The temperature you are talking about is the soil temperature not really the room temperature. The soil should be warm not hot. The ideal temperature is 70-75° f for the most chemical activity and to hasten nutrient uptake. Soil temperatures above 75°f can dry out roots and kill them. It takes several weeks for the roots to grow back so watch the temperature.