Topping off a DWC between reservoir changes - Add nutrients or not?

[JohnC]

Hi folks,

I'm getting ready to start a DWC grow for the first time and I have a question about topping off the reservoir between changes.

I will be using a 10-gallon tub with five gallons of water supporting a single plant. When topping off the reservoir between weekly changes, do you top off with PH'd, nutrient-filled water or do you skip the nutrients and just add plain PH'd water?

[Graff420]

Depends on the plant and the preference of the grower i nute my fill up water but i only add like 75% of what i would normally add to my one gallon jug when i do weekly res change lol my plant seems to do good with it just make sure not to over do it but plenty of people add only plain PHed water between res changes and their plants do great

[alltatup]

Hey John, I myself never add nutes but once a week, I'm usually at least 50% the recommended dose of nutes on a regular basis. Light is the fuel, and the nutes are supplements.

[POKEDSMOT]

I top off with pHd water and and 1ml beneficials only.

[alltatup]

I should start doing that when I top off...

[GanjaGed]

And I, lol, decide based on PPMs and PH. PH low - plain unPh'd top off or add a little silica.. PH high - Ph'd top off and pretty much anything besides Silica chosing what to use according to PPM, growth stage, and what if anything the plant is saying it wants/needs.

Like Poked said small doses.

[Sammy]

pH water maybe a splash of hydroguard that's what I do. Weekly changes with about 1/3 strength nutrients. ☮️

[alltatup]

I LOVE to see my plants thriving on way less nute than the recommended dose!!! It's the only way I save money on this darn hobby!!!!!

[IanHale]

I top off with Ph'd water. Same for my foliar spray bottle

[gbauto]

I find the ppm increases with water loss(as I'd expect) so I just add water to restore level and get the ppm back down to where I want it.

[ellz]

I have done it both ways. I used to only add HydroGuarded pHed water during top offs. However, this last time I mixed up a batch with HydroGuard, Cal-Mag, and about 2/3 strength of the base nutrients to try it. The plants seem to like it either way!

Here is my thoughts on the whole thing...

When you mix up your nutrient rich water, you are making it a certain blend. When you add only regular water to that mix, you thin it. If you don't mind thinning the mix out during the week, then only add pHed water with maybe HydroGuard. If, however, you want to replace what was lost use a nutrient mix. The only thing about it is that the plant can only take in so much before it becomes overloaded. If you notice problems from over abundance of nutrients, only add pHed water. If, however you add pHed water only and they look like they have a deficiency, then add nutes. From my personal experience doing both things, the best I can say is try either one but watch the plant closely when you do! The plants will always tell you what is best.

[alltatup]

Precisely. Nutrient lockout is what we want to avoid. Which is exactly why I don't add nutes more than once a week for hydro.

I'm assuming that by the time the plant has "drunk" a bunch of water, it has absorbed nutrients that are now doing their thing inside the plant. I add only pH'd water.