I’m using a recirculating Hydroponic (Hydro Farm). Is it best to add nutrients to the exsisting water solution, or drain it and add nutrients to fresh water?
I’m a soil grower, but I think most guys change it out completely at least once a week, but I don’t think a “top off” could hurt as long as you’re hitting the target pH/PPM in the end. @Bogleg, can you help us out?
You can top off and add nutrients in your top off - no need to change the entire res. That being said, the general recommendation that has been given to me by others is that once you’ve replaced the total volume of water via top offs, you should drain the whole thing and reset it with a fresh batch of water/nutes.
So, if you have a reservoir with 5 gallons of water in it, and every couple of days you need to add a gallon of water to it, once you’ve done that five times, do a complete change.