Newb grower. Many questions.

This is my first real grow with proper equipment and purchased seeds. I am quickly approaching harvest and I have kind of guessed and winged it so far based on my research. I have so many questions. I guess I should give some details as to what I am doing. Grown under MH/HPS in a mix of promix HP and sunshine #4 with dolomite added. Watering with reverse osmosis and GH flora series nutrients following their simple drain to waste feed plan found on their website. Alternate plain water every other watering.

So here are some questions that come to mind.

1. Is growing in a soilless medium considered hydro or soil? I am never sure about this. What section would be appropriate for posting or learning about this?

2. What is the proper pH for soilless? According to charts I have read 6.5 is optimal for soil while 5.8 is optimal for hydro. How do I treat the pH for soilless? I've read everything from 5.8 to 6.2 to 6.5. I have been pH'ing always to 6.5.

3. pH in or pH out, which is more important? and does pH out represent the pH of the medium itself? As previously stated I always pH to 6.5. My runoff will vary from 5.9-6.2. Does this mean I need to water at a few points higher? or simply add more dolomite to my mix next time?

4. Using reverse osmosis water and GH Flora 3 part, do I need to supplement Calcium and/or Magnesium? and can I overdose these? I have read the flora series is fortified with cal and mag already but I have also read these NEED to be supplemented when using r/o water. I have been adding a silica supplement on plain water days as well as a 1/10th strength CALiMAGic to give the ro water a little something. Can I give too much? I believe I experienced some kind of deficiency, burn or possibly lockout on one of the plants during this grow. No clue if this is why. Pictures available if needed.

I would love to learn to tweak things and learn from my mistakes so I could do even better next time. I look forward to learning.

1) It's either called hydro or soilless, as there's no soil

2) 5.5-6.5 pH for soilless (I stick to about 5.8 for my soilless grows). One thing to note though, is that some nutes will only be absorbed at a higher or lower pH, so I like to go up to ~6.2 and down to ~5.6 every few feeds to ensure the widest uptake possible.

3) I haven't ever had the need to check runoff as what I put in has always worked and I've never had a pH problem. Hopefully a more experienced hydro grower can answer this one

4) Someone else can help with this one too. However, Cal/Mag deficiencies are typically easy to spot. I just add in a tiny bit every three weeks or so for good measure, and of course up it a bit if the plants tell me they need more.

Best advice is to let your plants speak to you. Especially in your first few grows, look closely every day at your plants. This will help you create a baseline in your head as to what appears normal. After that, you'll start learning how to adjust things, and when.

If your first grow was successful, just stay the course without changing much. Also, never change more than one thing at a time. If you do, you'll never know what fixed a problem, made one worse, or created one in the first place.

-spek

Thanks spek9! I very much appreciate the response.

Interesting. I have read folks in DWC like to do a bit of a pH swing to allow efficient uptake of the whole range of nutes but I just never considered it for soilless with not knowing exactly where to be pH wise. I check my runoff religiously because I have read that peat has a tendency to drop in pH throughout the grow if not enough dolomite was added. Since being quite newb I figured I should keep an eye on this so I can spot if there is a problem easily.

As for the cal/mag. I am more worried about overdoing it as opposed to having minor deficiencies. Just not sure if it can actually hurt to add the stuff when there is some in the GH Flora, and if I NEED to add it to the reverse osmosis water, especially on plain water days.

So far, it's going quite well. I just want to learn to "dial it in" and these are some questions I haven't found definitive answers for through my research, which I feel might help me get this dialed in if I knew the answers.

Cheers!

1 - Soil-less would be like air rocks or wool mat.

2- As above said 5.5-6.5 is best. Watch it carefully if its soil-less any problems will develop in hours not weeks.

3- In soil-less you should test the in and out PH. Your run off is most important it tells you the ph of the plant/medium.

4 - based on your nutes and regime you likely do not need cal-mag.(some require) Although its easily confused with nute burn or spash.
Best is to focus on your base NPK once proficient then consider Boron then add your silicon to complete your plants cycle.

You are correct R/o water has near 0ppm so it need minerals and nutrients to feed a plant properly; but plants like pure water too! Just be sure to PH the plain h20 too.

A lot of answers are scientifically defined, others are based on the experience of individual growers so they vary widely. As I said, in a couple of the answers, hopefully someone with good specifics will speak up.

I'm about to do my first test with coco coir with a couple of my clones, so I'll test runoff just to see the difference, and keep notes as to what the diff is if plant issues occur, then what exactly I have to adjust to fix them.

Regarding RO and calmag, I don't know, as I've never used RO. Again, I wouldn't personally add any unless the plants require it. A few growers (experienced) here on RIU say use calmag every 3-4 feeds in RO after doing a quick search. Goes with my current theory add it in every few weeks.

-spek

BluJayz said:

1 - Soil-less would be like air rocks or wool mat.

2- As above said 5.5-6.5 is best. Watch it carefully if its soil-less any problems will develop in hours not weeks.

3- In soil-less you should test the in and out PH. Your run off is most important it tells you the ph of the plant/medium.

4 - based on your nutes and regime you likely do not need cal-mag.(some require) Although its easily confused with nute burn or spash.
Best is to focus on your base NPK once proficient then consider Boron then add your silicon to complete your plants cycle.

You are correct R/o water has near 0ppm so it need minerals and nutrients to feed a plant properly; but plants like pure water too! Just be sure to PH the plain h20 too.

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Cheers man! I'm lovin your answer for number 3! I suspected that the runoff might represent the pH of the medium but wasn't sure! Is growing in peat not considered soil less? I thought soilless was simply any inert medium.

spek9 said:

A lot of answers are scientifically defined, others are based on the experience of individual growers so they vary widely. As I said, in a couple of the answers, hopefully someone with good specifics will speak up.

I'm about to do my first test with coco coir with a couple of my clones, so I'll test runoff just to see the difference, and keep notes as to what the diff is if plant issues occur, then what exactly I have to adjust to fix them.

Regarding RO and calmag, I don't know, as I've never used RO. Again, I wouldn't personally add any unless the plants require it. A few growers (experienced) here on RIU say use calmag every 3-4 feeds in RO after doing a quick search. Goes with my current theory add it in every few weeks.

-spek

Click to expand...

Thanks again spek9! THis makes me think I should be taking more notes. What kind of things do you take note of? Dates and times? PPMS and pH? that kind of stuff?

I wish I didn't need to use RO water because in a sense it just further complicates things, but my city tapwater is horrible with a pH >8 and >300 ppm.

Specific pH, PPM, temp, humidity, amount of water fed, time of day fed, whether calmag was put in, specific plant health and usually snap a pic I can refer to later on if needed etc. Note that I only use a 2-part nutrient for hydro/soilless, and calmag is the only extra thing I put in. For soil, in some plants I use the same 2-part hydro nutes, and other plants I use Iguana Juice organic.

I only do this when I'm testing something new (new medium, new method etc). For plants/methods I have done previously, I don't document anything. I just grow and watch

-spek

Correct! Sorry that's what I meant by wool. Moss would be soil-less but more likely a drip system and not a full hydroponics. I would consider Hydroponics to have roots fully submerged like ebb and flow or sitting tank.

Not to steal spek's question; but I wanted to comment on the R/O water part. It does complicate things in a sense but you would suffer more issues not using it. Especially in a soil-less environment where you don't have the abundance of microbiotics working to balance the soil. It's almost your 24/7 job to be sure that water is near perfect for maximum yield. And R/O water helps you maintain the perfect balance.