Some rambling thoughts from my notes. I found this in an old journal I was keeping. It was my second or third hydroponic grow. In a few weeks I’ll be starting bloom nute feedings and I was looking for notes on how I used to do it…I seem to be forgetful in my old age. Anyway, I believe they still hold true today. It’s good info if you’re a DWC fan. Enjoy!
Bloom Week 3-8
PH 5.8 - PPM ~675 @ 4
4
4ml Micro
8ml Bloom
4ml Liquid Blue
3ml Carbs
CalMag as needed
At week 5 all CalMag is removed and replaced with MgSO4 to assist in ripening. The extra Sulfur seems to help a bit.
*The ideal scenario you are looking to achieve is where the EC is either dropping slightly or remaining static, with a static or slightly rising ph and a dropping water level. If you get this situation, keep doing exactly what you are doing because your plant is feeding and drinking.
Note 1. When pumping air into a nutrient solution in order to add Dissolved Oxygen, not only oxygen is present, CO2 is also pumped in. If you live near a busy road, this may be higher than normal, so you may get a dropping ph quite often. I have noticed most of the growers who suffer from a falling ph in DWC tend to live in large cities. This may not be a link but it could be. When CO2 is added to water, it makes it more acidic. This is the precise process which causes acid rain, pollution from power stations etc pouring CO2 into the air, this mixes with the water vapour in clouds causing acid rain.
Note 2. Most people assume that with a rising EC, it is the plants way of saying, I dont want more food, here, have some back. What is actually happening is this. Plants roots take in water/nutrients through a process called Osmosis. Effectively, if you think in terms of the roots having their own internal EC. The osmosis process will always try to balance out the EC's, taking from the higher side of the barrier and giving to the lower part. So if the EC of the nutrient solution is higher than the "internal EC", then food & water will flow from the solution to the roots, this is the normal process. If however, the EC of the solution is higher than the "internal EC", then the balancing will work the other way and nutrition will be leeched from the roots to the solution. A res change or increase in EC should resolve depending on the other factors such as ph and water levels.
Note 3. Nutrients flow around a well hydrated plant much more effectively and faster than one which isnt as well hydrated. How can growers use this? By feeding at lower levels, the plant needs to take on more water in order to get the nutrition it requires. So by feeding at moderate levels, this forces the plant to drink more. By drinking more, it is better hydrated, because it is better hydrated, it needs more food, making it eat more. So feed at moderate levels rather than overly aggressive levels. The method of pushing the EC until you see signs of nute burn is damaging to the plants and although many growers use this method, I am not a fan though your plants are not mine!