Drooping plants, top of coco white substance

[Meg2468]

Hi everyone! First time grower here. Growing two plants indoors in coco following instructions and nutrient guide on this site. One plant is Gelato, one is Northern Lights. Gelato was over watered at the seedling stage but roots looked healthy when it was repotted and it has since caught up growth wise after being a bit stunted.

Current problem: Plants are consistently DROOPY and coco has a white substance on the surface. I can't tell if it is mold or residue from our hard water. pH of the coco is normal at 6.5 and I always measure the pH of the water/nutrients and ensure it is between 5.5-6.5 before use. Have ruled out wind burn. I am waiting until coco is totally dry on top, light brown 4+ days between watering because I am worried this is over watering. Since I was also worried about underwatering I did the napkin test and confirmed the coco was still moist so waited to water. Colour of the leaves seem normal to me but this is my first time growing so hard to know. Very few leaves have yellow or brown spots on the tips. Northern lights plant also seems to be growing at a significant angle.

Note: the photo of the white stuff in the soil also shows a leaf with brown spots. This is left over from when the Gelato seedling was over watered and is not new. I have a second photo of newer brown spots that might be more relevant.

Temperature has been within 70-80F since the vegetative stage
Humidity has been low 60s since vegetative stage
Lights are on a 18/6 cycle

Appreciate the help and happy to send more photos or give more info if I have the tools to provide it!
Meg

[Gingerbeard]

I'm no good at diagnosing other folks's nutrient issues and such so I'll talk about the coco and water, since you mentioned it.
Take yourself a bit of H2O2 and put it on the coco. You can't put too much and you can put it straight. If the white bubbles, you have mold or some other living thing. If nothing happens, it could just be a thing. What brand coco/perlite are you using?
Where are you, generally? Someone in here might be close and have something to say about your water quality.
Get your bags off the saucers. Chop-sticks work well.

[Meg2468]

I appreciate this so much, thank you! I will grab some H2O2 today and report back. I'm in Toronto. Coco is Fertazin. I had a hell of a time rehydrating it because the brick was too big for my space. Perlite is miracle grow.

[Meg2468]

Tried the H202 and there was no reaction at all. The whiteness also seemed to has lessened with the more damp soil so I think it is just a "thing". There is some moisture under the bags so I will take them out of the saucers and put them on some chopsticks. Thanks for all the tips!

[Gingerbeard]

Could very well be your home mixed coco is just dusty.
Judging by the condition of the bag, there haven't been too many waterings since transplant or you have been running it on the dry side. Don't let your initial overwatering issue cause you to underwater.
In my experience growing coco in bags, the best way to tell if you need to water is by weight. My 5-gallon pots each get 1-gallon of water. Might be three days between. Might be four. Might be five. Pots need more frequent watering (not more water) as plants gets bigger because there are more roots absorbing the water.

[Bluey]

I'm in coco and I never let it dry out. I water between once every two days at seedling stage through to 3 or 4 times a day mid/late flower. I use nutes every water at about 65% of that recommended by the manufacturer but monitor that closely. I runoff about 20% two or three times a week now.

Tighten your pH. If you can get an Apera PH60 or the other one that does EC as well. Dont bother with the bluetooth phone app model, its a waste. Apera have a shop on Amazon and get calibration fluid and storage solution with it as well. 5.5 is way too low and 6.5 is too high.

Your using fabric pots with coco/perlite mix with every 4th day a watering? They are well and trully underwatered.

I don't know what's on top of the coco.

Using hard water may make it difficult or impossible. What is the EC of the water on its own? Others know more about working with hardwater than me. I've never encountered that. There are further resources online.

Knowing how much light you are giving them is an important factor even for seasoned indoor growers. Most of us measure the light, many using a smartphone app called Photone or PPFD Meter but you must calibrate to a known source to get half decent readings. Read up on PPFD and DLI and go from there.

Your temps and RH seem fine.

They will fully recover and perk up once you sort the above.

Good start for your first time.

Use a jeweller's loop or a usb phone camera with magnification to check for tiny pests from time to time. I hope you dont have a pest problem.

[Gingerbeard]

What B said about never letting coco go dry. I had run on the dry side but have had seemingly better results with more water.

[Meg2468]

Thank you for all of these tips! I will get to work on them. I am less concerned about the white stuff being mold/pests after doing some follow up but will get something with some magnification just to take a good look. Sounds like a good thing to have on hand anyway. Will get these ladies more water and hopefully that helps. Thanks again!

[No3odiesShad0w]

What kind of Coco are you using? Brick or pre mixed (pro mix, coco-loco)? They look like the EC was high or they could be salty. Magnesium lockout. I'm not a pro with Coco but I have been experimenting with it as a base substrate for living soils in comparison to peat. I've had a similar situation with my purple punch Auto. The Coco wasn't buffered properly and I ended up getting magnesium deficiency. Bluey knows his stuff when it comes to Coco. If anyone's going to give you sound info, it's him.

The white on the soil is perlite? Or am I missing something? I don't see bugs or anything odd. Maybe it's a pumice/perlite mix and just looks different because it holds water differently?

Coco likes being wet. Even when you think you over saturated it, it's probably fine because it can still give the roots oxygen. That's a specialty that peat based should don't have. Because peat is so acidic, it quickly dissolves oxygen molecules. That's why you need dry balls with peat. With Coco you can get oxygen to the roots even at full saturation because Coco is very pH neutral but also because it's a hydrophilic material, whereas peat is hydrophobic.

[Meg2468]

I used a brick that I mixed myself. Coco is Fertazin brand and I mixed with MiracleGro Perlite. Bluey said the white on the top happened to them too when the coco wasn't wet enough, and I have also noticed that it disappeared when I started saturating it with water more. Thank you for the reassurance that it likes being wet!

[No3odiesShad0w]

As long as you flushed the brick with a little bit of water before mixing it then you should be fine otherwise if you didn't flush it you might have salts.... And not the good salts

[Bluey]

I did a test and if I let the top of my always moist coco dry out I too get a white substance on top, so I'm guessing salts.

[Meg2468]

Yes! As I have been keeping the coco more moist I have not seen the white substance on top anymore.

[Bluey]

Make sure you wash your excess salts out of the medium by giving it run off from time to time. Early in the grow I don't bother but then it's important to give it good run off or a flush before transitioning to flower then I give it good runoff at least once a week.

[No3odiesShad0w]

That's weird I never got that with Coco but then again I don't grow with mineral fertilizers. I use all organics so different mode of nutrient transmission