Runoff at 4000 ppm right after feeding..... flush now or wait?

No real need to flush, just stop over fertilizing! This plant is burned from excessive nutrients. Flushing can release even more nutrient salts and accelerate the burning and make things worse, not better. Plus it destroys the soil biology. In soil, I have found a schedule of plain water/plain water/fertilizer to be safe and effective. Always ensure you water thoroughly and deeply to achieve run off each time you irrigate and this will help to prevent nutrient salts from building up to toxic levels and causing burning. If you are determined to do a "flush", no need to wait for things to dry out, flush whenever you are ready. You are going to saturate the pot anyhow.

Flush it to the same level of your water. Make sure you have additives like Humic Fulvic acids, mycorrhizae, trichoderma to rebuild the microbiological structure of the soil, with some roots enhancers. Then you will have to calculate the perfect ppm depending on your light Wattage and plant life cycle to fix the soil EC at the right level. Follow this video, Mixing Nutrients The Perfect PPM Calculator For Any Light And Plant Count : - https://youtu.be/tp2qI4tBox8?si=7_SYOeb-18OEfh_3

​🌟 What You’re Doing Right ​First off, kudos to you for actually measuring your runoff. Most growers fly blind and only realize there’s an issue when the leaves start canoeing or burning. Collecting that 200 ml sample shows you’ve got the discipline needed to master the craft. Monitoring ppm (parts per million) is the "blood pressure check" of the plant world—it’s the only way to know what’s happening in the root zone. ​🔍 The Situation: Salt Accumulation ​A reading of 4000 ppm is a major red flag. In most mediums (like coco or soil), you generally want your runoff to stay within a 200–400 ppm range of your input. At 4000, your plant is sitting in a "salt bath." ​The Problems: ​Osmotic Shock: When the salt concentration outside the roots is higher than inside, it can actually pull water out of the plant, leading to "burnt" tips or total lockout. ​pH Swing: High salt concentrations usually cause the pH in the medium to crash, making nutrients unavailable even if they are present. ​The Fix: Do not wait for the medium to dry out. If you wait, the moisture evaporates, and the salt concentration becomes even more intense (think of a puddle of salt water drying up—it just leaves a thick crust). ​Flush Immediately: Use pH-balanced water (with perhaps a very light "clearing" agent or 10% of your usual nutrient strength) to wash those excess salts out now. ​Volume is Key: Pour through roughly 3x the volume of your pot size until the runoff ppm drops to a safe level (usually under 1500 ppm for soil or 1000 ppm for coco). ​The "Reset" Feed: Once the runoff is clear, finish the flush with a light, balanced nutrient dose so the plant isn't left with "empty" roots. ​How to Avoid This: ​Increase Runoff: Ensure you are getting at least 10–20% runoff every time you feed. This "washes" out the old salts from the previous feeding. ​Alternate Watering: Try a "Feed-Water-Feed" schedule. Give nutrients one day, and plain pHed water the next. ​Check Input Strength: If your ppm is climbing this high, your base nutrient dose is likely too strong for the plant's current growth stage. ​💡 Pro-Tip ​Think of your growing medium like a sponge. If you keep adding soapy water without ever rinsing it, the soap just builds up until the sponge is useless. Frequent, smaller rinses are always better than one massive emergency flush! 🚀