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PPM - Does it Include Source?

I use bottled water or brita filtered. The PPM of these is between 80 and 200ppm (not good huh?).

Do PPM calculations include the source water? Like should I subtract that number first?

Also I have a 600W LED - have far should I keep it from my clones / seedlings (they are about a week and are doing good I just dont want to ruin them). Does anyone have chart or something that shows how close the light should be throughout the grow, by wattage?

Thanks this forum is great.

4 answers6 replies

Comments (10)

Mr. Grow It

Jul 12, 2020

I agree with @gregthe357 , that's a great tip. Another indication that your plants are happy is if their leaves point up towards the light as if they are "praying". However, some plants droop down before lights off, droop down after being watered, and many also don't pray like that in flowering so don't use praying as an indication 100% of the time.

vapeape

Jul 14, 2020

Replying to

Thanks both of you @gregthe357 and Mr G.!

A few pics - they are doing good now (in my opinion). I know it may not be correct, but I topped the two tallest plants yesterday and started a little LST on one. Should I have waited? (I raised the others as you suggeted).

Mr. Grow It

Jul 15, 2020

Replying to

@Tim Your plants look great man. It's cool to see that you're trying out training. Nice job. I actually just filmed a discussion video talking about plant training techniques with Pigeons 420. I should have it out in the next day or two on my 2nd channel. I think it will be helpful to listen to in order to generate ideas on how you want to train.

gregthe357

Jul 12, 2020

Hold your hand right at the top of of you plant and keep it there for 15 or 20 seconds, if it starts to feel warm to you then the plants will feel the same way. If not then you are golden.

vapeape

Jul 11, 2020

@Mr. Grow It

Thanks for all the info, very helpful. I moved the lights in both tents to approximately 20" away. How can I tell when the light is too close, do the leaves turn colors, turn upward or downward, wilt, burn etc?? How can I tell when the light is too far away? Or asked another way, besides "healthy" looking plants (which can be subjective), how can you tell when the lights & nutes are "just right"?

Mr. Grow It

Jul 09, 2020

That PPM for your bottled and filtered water isn't bad. My tap water comes out at 485 (for comparison). Yes, include that PPM in your total.

Which LED grow light do you have? Not all LED grow lights are created equal and your best bet is to look at their PAR chart or go by the manufacturer's recommendations. Wattage can be misleading when it comes to LED grow lights because some manufacturers list the "HID equivalent" instead of actual wattage.

BTW looking at your pic it looks like some plants are struggling a bit. My initial guess would be overwatering but we would need more info. Do you feel you have those plants under control or need guidance?

Mr. Grow It

Jul 09, 2020

Replying to

@Tim According to the grow light's listing, it emits 402 PPFD at 24" away. That's the dead-center reading. I assume there will be quite a bit of drop off as you go outward from the center. I would probably run the light at about 20" and see how the plants do. How far away is the grow light right now?

Wow! I've actually never seen a grow tent collapse that bad. I'm glad to hear they refunded you.

The clones are what look to be struggling (3 bottom left, 1 top right). If they have rooted like you say, you may want to let the medium dry out to see if they bounce back. Sometimes the medium is too wet and compact so plants don't get oxygen into the root zone and slowed growth occurs. Just a suggestion. Do whatever you want of course :)

vapeape

Jul 09, 2020

Replying to

@Mr. Grow It The height was about 25, so I just lowered it 5 inches - I'll let you know how it works, and I'll let things dry out a bit. That brings up a point tho, do you measure to the top of the shortest plant or the tallest? Same question for my flowering plant - the tallest bud sites are 6 or 8 inches higher than the shortest. should I split the difference? I dont want to burn anything but the shorter ones are definitely not getting same intensity.

I took one of the clones outside for better pics - in my opinion these clones look ok, and at least they are alive (I didnt think theyd survive!). There were lots of roots sticking out the cubes before I planted in soil (I used myco too) Do you think they'll make it? Any other suggestions? You may recall that these clones were very small to start with and they all had small buds. I took them so late because the plant got crushed and took a long time to recover. Thanks again!!

Mr. Grow It

Jul 10, 2020

Replying to

@Tim Measure from the tallest. One thing you may have heard other growers mention is the importance of an even canopy. The reason is so the plants don't have a height difference, and therefore, get an even amount of PAR. Some growers will place smaller plants on top of something (i.e. a crate) in order to make them even with others. If your grow light emits a hot spot in the center and then PAR drops off towards the edges, keep that in mind. In same cases you can use that to your advantage like by placing seedlings around the edges where PAR is lower and plants in Veg more in the middle where PAR is higher.

Oh yeah now I remember those clones; the ones you monster cropped. Yeah I'm sure they just need a little time and air into the root zone to see some good growth.