How the heck do I flush right?


I’ve been reading the grow Bible and a lot of posts from others about flushing everything out of the plants at the end of flower. Most say 3X water for the size of the pot you’re growing in. I grow in a 5’X6’ room and have 10 plants in 7 gallon smart pots sitting in big plant saucers. I don’t see how I’m going to give them 21 gallons of water each. I took three of the plants that are less than 3 feet to the bathtub and flushed them. There’s no way I can take any of the other plants to the bathtub. They are 5 to 6 feet tall. I’ve been hitting them with a gallon every 2 days, but the PPM of the runoff is still high (400 -700). I’m guessing that there are others with the same issue. I have a small shop vac, but it will only suck up 3 gallons and it’s full. Surely there’s a way around this that I’m just not seeing.


Hope this helps:



Thanks. I read the whole thing a couple of weeks ago. I still am stuck on how to deal with a massive amount of water that I apparently need to get the PPM to near 0. Do the flushing solutions out there need much smaller amounts of water to work? I need to join the paid forum and will as soon as I can.


Have a shopvac? Water slowly, and a sick it up as it begins to accumulate.


Your nutrient line may have a flushing agent so you don’t have to use so much water. Take a look at sledgehammer from Fox Farms. @skgrower


Boy is that going to take a while! I guess I have no other option at the moment. I am going to look into a flushing solution. Like @bob31 suggests. Getting down on the floor to water is a real problem for me. I end up out of commission for the day with only a 30 minutes of doing any of that. I need to come up with a low dollar automatic watering system that I can experiment with a couple of plants to get it set up right.


One of the members built a system so he didn’t have to bend over. Using like funnels and hose. Seemed to work well.

Here is what I use. The handle locks open so I can pump it up and walk away.


I bought the green thumb mode lat my local true value. It was only about $15- I think. The sprayer tip unscrews and lets out a nice smooth stream for watering. Works perfectly!


I hear ya! I didn’t put a whole lot of thought into the 7 gallon pots lol.

I typically run between 1 and 3 gallon pots, and my method of choice leaves pretty easy access to the pots. Nor do I use flushing a whole lot. @bob31 has a pretty good recommendation with finding a flush agent.


@skgrower I have a suggestion. Where is your grow test located? Is it near a water outlet? If so, put a cooler under the outlet, and run a small hose from this pump (link underneath) to each plant. You can do the amounts you want and that you can observe. Then reverse the hose back to the cooler and pump the outflow back. That is if your pot is in something that can contain the outflow. I have mine in a tub that will catch up to 2 gallons of outflow at a time.

pump here.


It’s not close enough. I’m trying to figure out how to adapt a male water hose fitting to a shower outlet. Probably going to have to sweat something myself. I could get a hose much closer that way. I have to figure a much better way. Next grow is 14 plants, even with an automatic watering system, a flush will have to be manual. I used G.H. nutes the whole grow and with smart pots you can see the build up of salts. One good thing is the next grow is 3 and 5 gallon smart pots. I have a nice water pump because I sleep on a water bed. Thanks for the suggestion.


Thanks for the new link I didn’t have that one yet lmao I have had to explain flushing more than a few time that will make my life easier :slight_smile:


1/2 inch female NPT to 3/4 GHT male or female I guess @skgrower
I buy this stuff all the time ace hardware brass plumbing section.