LED Grow Light Forum

This is my first hydroponics grow. I'm beginning to learn there is a nice size learning curve!
It seems like every day or two I go down to my grow room and find another issue that needs resolving. The last time I noticed that some of my tomato leaves are starting to curl down. Also, my cucumber plants have started to produce it's first set of true leaves, but I'm thinking they are a bit pale. also the tips seem to be dying
A bit about my system:
400w led solar storm (32" above plants)
60 degree night, 72 degree day (16 on, 8 off)
Fan blowing over plants now...was oscillating directly at plants before
Ro water
Approx 1050 PPM
3 part with calmag
Been running about 3 weeks
Nutrient level stays fairly steady (PPM) as water level decreases.

I just get the feeling like things are growing slow.
I'm unsure about the distance of my light.
My setup is an NFT, BUT when I inserted my netcups in the 3" PVC, the bottoms didn't touch the water. I leveled the PVC and now the level is about half way up inside.
I have an airstones right by the water pump.

Anyone care to have a crack at this mess? Lol

Well, you left out some basics, (like pictures) but let's see if we can help...

pH?
Reservoir size?
Nutrient pump gpm/gph?
Nutrient temp?
hydroton/rockwool/coco?
plant spacing and age/growth stage?

It may be that 1050 ppm is too much for them or it could be a pH/nutrient lockout. It's hard to say right now. Pictures and more data might help...


SME

pH 5.75
30 gallon reservoir
Pump 400 g/h
Nutrient temp-64
Started seedlings in rockwool, did not remove it when I transplanted to netcup with hydroton. I placed the bottom of each rockwool cube in the netcup so that the bottom of it just barely touched the nutrient solution. Otherwise I thought there would be no way for the rock wool to draw up any nutrients for the plants. Roots had not grown enough (for the most part) to grow out of the rockwool.
Spacing- about a foot
Some of the plants have good roots started and are nice and white.
I'm about 3 weeks in I think. That's why I was thinking everything is growing slow.

UPDATE
I flushed my system out with water, ran clean water over the hydroton to rinse off accumulated salts, then drained all of the old nutrient solution.
I am currently running with 6 gallons, 64 degree water, 5.75 pH, 866 PPM (starting with 173 PPM water which was a mix of my 450 PPM tap and 15 PPM ro waters)(no calmag this time, since I used hard water for about a 1/3 there should be enough nutrients already in the water, yes?) (city water)
I'm planning on running more water if needed as soon as my ro system can generate enough.

Pictures to come later today, battery on camera is charging.

OK, I did notice a couple of small potential issues but I still can't say without seeing the plants.


You seem to have most of the basics covered but people often forget about things like temp, humidity, res temps, pH, etc...

1) With 450 ppm tap water try reducing your ratio to 25% tap to 75% RO. You *might* still need calmag but it depends on how much of what is in your tap water. You may want to add mycorrhizae, for root health, to your system too.

2) Are the less healthy plants the one that aren't showing roots through the net cups or the ones that are showing? Both? Rockwool holds a LOT of water so it could provide a situation where they are drowning from a lack of oxygen. You want roots in the water not the rockwool.

3) 3 weeks in from seed or clone with barely any root production may require less nutrients too. When they're all healthy, green and growing rapidly you can ramp up the ppm to almost as much as they can stand. You might also check the nutritional requirements/suggestions for your crops and make sure that they're compatible together.

4) You might also consider raising the ambient day and night temps by 3-5 degrees and see if that helps...


Hope that helps...

I'm usure about the humity actually. What is an acceptable range? I have a 10' x 10' area enclosed so it should not be an issue to take care of. Also, I don't know if I mentioned it before, but the area is heated by a vent I put inline in my heat ducting. Another bit of information is that I had an oscillating fan blowing directly at the plants before. Now it blows over.

I would like to not have to use calmag. I don't see the logic of removing nutrients, just to enrich the water. Not to mention wasting money. I plan on getting a copy of the city water profile. I'm unsure of what the info with show, but what should I be looking for on the profile? PPM of calcium, magnesium, etc? And what are ok levels?

My roots seem healthy. I see what you mean by the rock wool being super wet, but that raises a question for me. Do you try and remove the rock wool before transplanting to the system? Grow the roots past the rock wool? If so, how? The roots would dry out once free of the rock wool.

Is it normal for the hydroton to grow salts in the surface? I imagine it happens because the fan is off at night letting the hydroton get wet on the surface, and dry out when the fan comes on during the day.

I have roots in the nutrient water for the plants not looking well. On the switch side, I have a lettuce and 2 tomato platnts that are doing just fine. Perhaps it's time to lower the water level in the PVC from half way it to a third or quarter?

I can't find a good source of what PPM to shoot for for various plants. I've read lots of people stating one way or another, but they never mention what PPM water they started out with. I do have a list of PPM per plant, but it doesn't say what the baseline PPM of the water was or how much nutrients were added. Um, something just popped into my head. Does it matter what the 800 PPM consists of or is a plant that thrives at 800 PPM unable to take in additional PPM of say a 900?
Maybe I could use some clarification

Agreed on the raised temperature, I'll give that a try as well.
Pictures to come soon.

Thank you for all your help, the pressure in my head is coming down!

Here are the pictures
There is also a picture of my hydroton that was a space holder in my system.
Holy crusty right?!
I think this is what happens when you allow your hydroton to be wet on top and dont change the water often enough. Am I right?

I haven't done much indoor vegetable growing so I may not be the one to ask in regards to tomatoes and cucumbers but I'd guess that 40-60% wouldn't be out of line but that is just a guess.

The logic is that some muni and well water supplies are so bad that you'd get lockout issues and if you start with RO you know what they're getting because you have to add it. Your water report should tell you everything that's in it, how much and what safe levels for human consumption are at least. Don't get me wrong, I've grown a lot of plants outside with little more than 350 ppm tap water but 450 ppm tap water sounds a bit much to me. Let's see what your report looks like before you decide...

I keep the rockwool and net pots close the to top (out of the standing/flowing water) and then I water from the top until roots hit the nutes...

It may be that they're drowning. You could cycle your water pumps so they have some air time and see if they like that.

Generally when people talk about feeding at 800 ppm it's either not including what's in the water (or using RO water) because if they include what's in their tap that ppm varies from city to city. 800 ppm in one city may not be 800 ppm even in another if they both added 800 to tap. 800 ppm of nitrogen without anything else would be bad so it has to be a mix of the right ratios. Some plants like more ppm than others; and even the same plants might like more ppm as they get bigger or less when they're almost done producing. Some plants can take 800 ppm and burn at 900 ppm while other plants thrive at 1200 ppm. Growing methods may play a role there too but that's a long debate.

Since your plants are so small you might want to try less ppm and work your way up. In hydro they react pretty quick to environmental changes.

Looks like salt buildup to me...you can flush the top of the pots with fresh water now and then or lower the water level to keep the net pots out of the water.

When I ran with straight ro (15 ppm) I had about 1000 ppm. (985 ppm)

Now I restarted with 173 ppm water. With nutes, 836
So, if I understand what you are saying, I should be claiming I'm running at 663 ppm (836-173)?
Or is that wrong thinking because the ppm of my water DOES include calcium, magnesium, etc that should be included in the total ppm, which would mean I claim the reading get with my meter of 836?

Sorry if everyone else gets this, but I find clarifying things ahead of time gets rid of a lot of headaches down the road.

I increased my day temperature by 5 degrees. Now 77
I'm going raise the "water in" end of the PVC to lower the depth of the nutrient solution in hopes of giving the plants more air.
I should also note that I looked at the tomato plant that is not doing well...I started it in a plug (starts out as a flat disk and expands when you add water), so yeah, I'm thinking that one has to be drowning, no air gets into those if they are wet.

Good idea on not letting the rock wool touch the water and to top water until the roots reach solution. I believe I made that mistake because of another grow I am attempting with lettuce using the Kratky method (seen the netpots in the water 1/4")

Cudos to the hardcore hydroponics people, but I may try using soil in my basement grow next time around. BUT, still use my light I bought because I think it will pull off bringing plant all the way to fruit. (solar storm 400w)

Thank you for your help, I really do appreciate it!
My next post will be in the Grower Feedback for the California Light Works testing program.
See you in there!

Like I said, it's complicated so the short answer is...it depends.

Total ppm isn't as important as the amount of each nutrient and the ratios that they're found in.

If you're using RO or water that's nearly 0 just use the total ppm. (We'll call RO 0 ppm)
If you're using tap (Let's say 200 ppm)
If the feeding schedule that you're using suggests 800 ppm, that's minus the ppm of the water. (You added 800 to the 200 ppm water for a total of 1000 ppm)

So what's the difference between RO and tap? Whatever is in your water and that varies greatly. It could be good stuff you need or bad stuff you don't. 200 ppm of chlorine isn't going to help your grow.

If you're shooting for say 900 ppm of nutrients based on a formula on the bottle or on the web then I would add 900 to whatever the water is.

PPM is a guide not an exact nutrient formula. A good formula would have certain ratios of the desired nutrients (NPK, etc). For example, I like to use the Lucas Formula (or a modified version of it depending on needs) but ask a dozen people what their ppm is in their Lucas filled res and you'll get a dozen answers. The Lucas formula doesn't say what total ppm you want it's says how much (in ml/gallon) of each thing to add. In the case of Lucas he wrote the formula to use GH Flora 3-part series of nutrients but only the bloom and micro, not the grow. 8ml/gal micro + 16ml bloom + RO. The result is a profile that you can plug into a nutrient calculator to see about how much of each nutrient you have.

Another grower named Mel Frank proposed that you need a certain ratio (in ppm) of desired nutrients but you can look up his work and the Lucas formula for more details. Of course, Lucas and Mel were talking about cannabis not cucumbers so YMMV...

If you really want to use your tap instead of RO; get your water profile and plug the data into a nutrient calculator so you know how much of what you have and subtract that from what you want the levels to be. If you want to use tap water, adjust the Lucas formula. Maybe you'll need a little less bloom or micro, for example. If you're shooting for a certain amount of calcium, for example, and your water has none and your nutrients doesn't have enough, you may need to add something else to raise it up. If your tap water has more than enough calcium you may need to use a different nutrient that has less so your total ratios (not total ppm) are good. You can't just blindly add 600 ppm nutrients to 200 ppm tap water and expect that the ratios will be right unless you know what's in your tap water.


Yet another reason, for me, to use RO water. The PPM meter doesn't care what particles it finds; it just counts them so a total ppm can be misleading. RO is less confusing and good nutrients should have all of the micro nutrients but if it doesn't that means adding a little cal mag (etc) might be needed. There are nutrient calculators that you can type in all of the data like how much of what is in bottle X,Y or Z if you wanted to see what adding A, B or C amount of cal mag (or tap water) to your specific nutrients would do to the whole profile.



Hope that helps...