New Indoor Coco Grower Salt Buildup HELP!!

Hello all, I've been having some problems with my ladies which I have some ideas about but this is my first indoor grow and I'm using coco on the suggestion of a friend so I feel like that may have added another layer of unneccesary complexity for a newbie like me. I initially had a bunch of issues, underwatering, underfeeding, light too far away, not good airflow, basic stuff you have to tweak. I switched from distilled water to my tapwater and began watering them properly (for coco) and the TOOK OFF initially. I also added calmag at this point and started feeding them a bit more.
After about a week, I began to see twisted, deformed new growth, with some of the older leaves twisting as well. Growth has been pretty slow since then (about a week ago), and so Saturday I ordered a PPM meter (didnt know they were so cheap, wtf) and checked my runoff. it was about 300 PPM higher than what I fed it, and the pH was at 5.5 (I fed at 6.3). After doing a BUNCH of digging, I realized that there is most likely salt buildup in my pots (fabric). I think I was adding CalMag when I didnt need to and now they are in need of a good flush. I am about to do that now with a low EC nute solution, but I wanted some tips on how to go about that/prevent it in the future and to see if that is the only thing I need to correct.


Sorry for the long background but some of it is probably important. Here's my setup:

3x3 tent
intake/outtake fans & fan circulating air
medium: CANNA coco coir
Nutrients: FOXFARM growbig (using hydro now but initially used soil)
Light: Spiderfarm 2k LED (has Samsung chips and Meanwell driver)
Humidity: 50-65%
Temp: 68-71, 65 at night
18/6 light cycle
Fabric pots
Feed at 10ml/gallon (4 liters) or ~500ppm
Tapwater: 500 PPM (I know, its fucked)
4th week of veg, were tied down to spread out (hoping to scrog)
defoliated right before signs of warped growth appeared (adding to stress?)
feed/water once/day with runoff

Also has been showing what look to me like potassium deficiencies, which is why I switched over to hydro nutes. I then thought that they needed more nitrogen and that it was only getting worse, but that was two days ago and I realize now its almost all likely due to the salt buildup. As a side-note, for the 3 days between when I realized there was a problem and I picked up an EC reader, I was feeding light nutes and checking the pH of the runoff. It was steadily at 5.5 pH, and I think this is another indicator that there is salt buildup. I have heard molasses works, but I don't have access to any tonight or tomorrow (maybe) and I REALLY want to take care of this ASAP.

ANY and ALL help is appreciated here guys, and tbh I feel like a huge dumbass for not thinking about salt buildup.

umm u need a way to get lower tap that's gonna be the big problem

Gond00s said:

umm u need a way to get lower tap that's gonna be the big problem

Click to expand...

Yeah I knew that was gonna be an issue, theres no way around it? Waters expensive!

If you're in pure coco, your pH of 6.3 is too high. I would aim for a pH of 5.8.

I can tell you by experience, unless you're just feeding horribly salty feed (in other words feeding too much), you most likely don't have a salt build up issue. If you think you have a salt build up and you just have to do something about it, make up a new batch of feed, pH'd @ 5.8 and water your plant until you get substantial run off. This will reset your medium with the proper pH and it will help flush any residual salts that may have accumulated.

That's about the best I can do without seeing pics. Good luck friend.

Here are some pictures from last night, I found out I have access to well water that is at 380 ppm (better), and I used that to flush them last night untill runoff PPM was less than 400. Fed them afterwards at 700 total PPM and runoff was at 450 ppm, so thats good. hopefully they all bounce back from this soon, I was hoping to already be in flower by now!

Even a brita filter will help some buddy, I'm not sure how much, but it will.

looks like mag foliar feed some epsom

really late to this thread but did you find a solution and how'd they turn out?

MozzerellaFirefox said:

really late to this thread but did you find a solution and how'd they turn out?

Click to expand...

Lol........I think the OP is history.
He only made 4 responses and hasn't been seen on RIU in almost a year.