Once a dayWhat is your feeding schedule?
Are you feeding to substantial run off?Once a day
I feed till %15 run off, I don’t ever feed plain waterAre you feeding to substantial run off?
Do you ever use plain water?
Im embarrassed to say i do not know the EC of inflow or outflow. However, I have ordered a meter. The lights are 252w about 12 inch from plantsWhat is your inflow EC and outflow EC?
I know your pH is on point, but what point is that?
Are those 20W t5 bulbs? How close is the light fixture to the top of the canopy or what is the PPFD?
Im embarrassed to say i do not know the EC of inflow or outflow. However, I have ordered a meter. The lights are 252w about 12 inch from plants
No need to be embarassed some nutrients are fed by volume (grams/ml) and not by EC. What fertilizer are you using and at what rates? ml/gal etc?
I've had people tell me never to flush during the plants growth/generative cycle but since I started doing that I literally never have a problem and I can be assured too much salts or certain elements aren't building up to toxic levels in the rootzone.
Im embarrassed to say i do not know the EC of inflow or outflow. However, I have ordered a meter. The lights are 252w about 12 inch from plants
Right, but the amount of grams or ml's in their recipe are calculated by the manufacturer based its EC. This is why when using General Hydroponics 3-part, for example, growers have to cut the ml's down by 50-75% because the the EC is way too high for cannabis because tomatoes, cucumbers, eggplant etc., (what most of their customers grow) take 3.0-5.0 EC.
If you're feeding at the appropriate EC, you will never need to flush (seedling to harvest) and checking runoff EC will confirm that you're keeping the inflow EC at the proper level to ensure that you don't develop a salt build up.
Plants like consistency. When you're feeding it a certain EC, the plants have produced sugars to deal with the salinity of the feed they've come to expect, and when you drench it with plain water, it has to use growth energy to quickly convert those sugars to starches to prevent it from taking in too much water. Then when you go back to feeding a high EC, it has to expend energy on quickly producing sugars again to process the salinity of the water. Osmotic stress is placed on the plant with flushes.
I'm in large pots right now, there's plenty of nutrient still in the coco when I give plain water. I'm only shooting for 30% runoff with the plain water feed once weekly. I use a calibrated BlueLab Pulse meter to stab the coco and its still well over 2.0 EC a few hours after giving plain water in 10 gals. My EC after a normal feed are in the 2.5-2.6 ballpark. If I were in smaller pots (soon again I will, needed less waterings for travel) I would feed them like usual, then flush with water, then feed again within the same day.
Even if you feed the correct amount of nutrients, and allow 20% runoff, you can still accumulate salts/elements in the coco that could cause a toxicity issue. I would rather flush and be sure than hope all is well cause I've been bombing them with the same fertilizer solution.
I don't think periodic flushes of plain water are going to do any harm to the plants. I've done without, and with, my numbers are the same on my charts for yields.
I'm also not saying everyone should flush their plants once a week, but it's worth considering. Even every 20 days might be smart.
When you actually look at your plants and put the charts aside, you can tune your waterings in accordance with feeding each time, less or more, always in small changes, always consistent.
People think that if they gave 0.8 ec for instance, it should only go up from there, no... like @calvin.m16 said, salts will build up even at low doses and even when you allow runoff.
The best solution is to adjust everything beforehand to optimal conditions instead of chasing your own tail later on.
Roots don't like flactuations, flushing should take place only if you screwed things up beyond normal repair and as last resort.
The main problem is people get carried away, either in too much or too little without actually looking at the plants and understanding what is needed.
I always follow the plant, starting at my water starting point (usually 0.5 ec) and increase very slowly according to what the plants show me.
If I see over feeding, I know it's small above what was good, and I start to take it down also slowly until I reach again to a good condition.
Coco is subject to problems with salts, as most people just grow in dense grained coco which holds tight salts and even when giving less ec water, it still has a hard time getting rid of past salts in it..
A lot of factors going into play here,
That's why I always use ewc with my coco and adding salts very slowly after 1 month of growing.
If you're doing feed/water/feed, especially in the same day, you're feeding too high of EC. If you think about how DWC is, how the roots are constantly submerged in nutrient solution, the goal is to attempt to keep the EC the same 24/7 and only increase as the plant matures.
If you're at the correct EC, allow for 20% runoff, then the only way you will accumulate a salt build up is if you did dry backs.
How sea salt is made is by collecting seawater water in shallow pools and letting the water dry out and all that's left over after evaporation are salt crystals.
In coco that's allowed to dry back, the same thing happens - the medium dries out and the salt in the nutrient solution crystalizes out of solution and when you feed the next time to 10-20% runoff, the salt crystals raise the EC of the current feed causing the rootzone EC to spike. As this keeps being done the EC continually gets higher and higher and a flush is necessary.
However, if the plants are never allowed to dry back more than 10% and the EC is appropriate, then the salt never has a chance to crystalize and build up in the medium because you're constantly providing a stream of new nutrients at the same EC that replenishes the "old" nutrient solution in the medium hours later and maintains a consistent rootzone EC.
When I'm in full flower and feeding at like 1.3EC several times a day, my runoff EC is in the same range all the way to harvest.
I didn't say it would harm them; like humans, plants learn to deal with stress. An employee that is continually under stress, having to place time and energy toward tasks that are not directly related to their job of producing results for the company may still be able to produce well, but he or she would be happier if the entities responsible for creating job stress that isn't directly related to their assignments wasn't there and would probably perform better.
You grow good plants and give good growing advice on the forums, so all I'm saying is that this specific feeding protocol in coco is dated. Feeding at a high EC and then flushing every 3-4 weeks is not the optimal way of growing in coco because unlike in soil, you're feeding the roots directly. For all intents and purposes, the coco is just there to prevent the plant from falling over and it's a hydroponic method of growing.