I have grown a flask of Paph rothschildianum from flask two years ago and about 75 % of the seedling have a leafspan of 16 - 19 inchess across. My temperature minimum doesn't go below 20 C year round with humidity about 60 %. Is this normal?

Paphman

I have never grown any plants from flasks or compots so I can't really help but it sounds like your baby roths love your conditions under your HID system to grow so quickly in only 2 years. That is quite impressive! Most of my plants also grow quickly under my HPS system.

That is quite impressive!

i agree

Howdy paphman how far away from the lights are your plants?

Follow up to Tadd's question. What wattage HID are you using, and at what distance are the plants from the fixture?

TIA

Hi Tadd:
They are 24 inches below the 400 MH lights and about 1.5 feet from the centre of the lights. I water them every three days and fertilize it with quarter strength 20-20-20 supplemented with calcium nitrate and epson salt every other watering. The seller told me his seedlings are 7 to 8 inches across.

Paphman

Keep doing what you are doing.......That rate of growth is very good for roth. Don't drop the temperature until the plant gets mature and you want it to bloom.

Thanks Bill:
They like the warmth of a Phalenopsis and very bright light. I didn't think they will grow this fast and they are take up a lot of space.

I also have a mature Paph rothschildianum that I grow under the HID lights. I bought it 6 years ago as a 9 inch seedling. For two years growing on the windowsill it didn't do much. I went to the hydroponic shop and bought a 400 HPS system and my roth seedling doubled in size in one year. It flowered in 2004 on a single growth and a half with four large flowers. After it flowered, two new growth started and now the new growths have matured and they have new growths as well. Overall leafspan is about 33 inch leafspan and the leaves are almost 3 inches wide. I hope to get a digital camera in the near future so I can post pictures.

Paphman

Would love to see your roths, Paphman!! Sounds like they're very happy in your care.

~H

It is quite obvious your roths are flourishing in your conditions, so keep doing whatever you're doing and don't change a thing. Post pics if you can. I have tried growing slippers under fluorescents but they were such huge disappointment, plants were not too happy, droopy and growth slowed down considerably and right after I installed my first HPS system, all my plants actually perked up right away and have been growing and blooming very successfully ever since.

I'm curious as to what type of HID bulb you are using.

They are 24 inches below the 400 MH lights ...Paphman

is it just one light?

I am using a Phillips non coated 400 W Metal Halide bulb. I can only use one at this time because I live in a tiny apartment and the orchids took up the whole dining area which my wife is not happy with! I also have a 400 HPS system that I am not using. I like the Metal Halide over the High Pressure Sodium because it stimulates better growth than HPS. I think the hydroponic shop clients are mostly Cannabis sativa growers who prefer HPS for better buds. I was suckered into buying a high pressure sodium system to begin with. I notice my orchid have elongated leaves after 8 months of use and I wasn't happy with it so I changed to Metal Halide. So far no elongation problems! When I move I plan to use both lights in a bigger place. The area I grow it in doesn't have any natural light so a MH should have been recommended in the first place.

Paphman

I have been using a 430 watt HPS w SonAgro (both red and blue light spectrum) on a light mover and not one single plant showed any signs of elongation or legginess. :-dance:

Hi Peter:
I have the same type of HPS light bulb as you do. Come to think of it, it may have been due to fast growth but the leaves do eventually straighten out and a new leaf appears. I don't have this problem anymore. Do you grow your orchids under no natural lights?

Paphman

No natural sunlight just the 430 watt HPS w Sonagro.

Hi Peter:
I think the reason was the light was hanging 4 feet above the plants and it was 4 feet away from the centre of the bulb. Another thing wrong was the reflector had a lot to do with it. The reflector was a cheap and it did not reflect the light properly.

Paphman

Are you sure your 400 watt HPS bulb is Sonagro? I just noticed you said you have a 400 system and not a 430 watt and I don't think they even make 400 watt Sonagro HPS bulbs. So, I think you have a 400 watt dual HPS/MH system and you do need a different ballast to use the Sonagro HPS bulbs unless you are using one of the more expensive conversion bulbs. A regular HPS without any MH will cause "legginess".

Hi Peter:
The hydroponic guys sold me a 400 HPS and he told me a 430 Phillips Son Agro bulb is OK and it won't hurt the ballast. I do have a 400 Watt HPS ballast and a 400 Watt MH ballast. I plan to use them both eventually.

Paphman

Hi Peter:
The hydroponic guys sold me a 400 HPS and he told me a 430 Phillips Son Agro bulb is OK and it won't hurt the ballast. I do have a 400 Watt HPS ballast and a 400 Watt MH ballast. I plan to use them both eventually.

Paphman

Oh ok, got it! Another member who is also in Canada just bought a 400 watt HID system and he said he was not too happy his salesman sold him a 430 watt HPS bulb because he later found out that his system will only use 400 watt output and not the full 430 watt. Here is the LINK (http://www.slipperorchidforum.com/forum/viewtopic.php?t=2239)

Hi Peter:
I always wondered about it. I did get suckered into buying the 430 W Son Agro bulb for 69.99 CND. The ballast still works and I plan on using the 400 W HPS Son Agro in the near future. Thank you for pointing that out and you are so kind to share your knowledge on this forum.

Paphman

You're welcome, anytime! :D