Water output vs input on hydro system

[cybergenesis]

My brother said, that in a hydroponics system (such as the one in my bedroom!) that you are supposed to have about 10-20% of the water you spray onto the plants, coming back out as waste.

 

However I noticed my main water tank, was doing down about 2 litres per watering (which is twice per day), yet about 1.5 litres of waste water was being pumped out into the waste water system.

 

Thats about 75%...

 

I have a valve, which lets me adjust how much water is going directly to the plants to water them.

 

I turned this down, but when I did so, I noticed that the water doesn't spray very far into the pot, into the coco, rather almost dribbles just around the outsides, so I worry that watering it this way will NOT get water into the center where the roots are.

 

I use an electronic timer, which turns the water in for one minute, twice per day, but you cannot set it to be on for less than one minute.

 

The plants are only 3.5 weeks into veg, so are not large yet (though they are going well enough).

 

Is it critical to get this water issue right? Does it make a significant difference to yield in the end? Is it important at this early stage? Or is it more an issue for flowering?

 

Any advice is very appreciated. I think this is the only thing left I have to master! Well for a while until they get to flowering stage.

[The Hash Nibbler]

If you can and you have not too many pots maybe try hand watering and yes 15% is the desired amount of run to waste. Coco holds water well in larger pots, but if you got lots of little ones then dripping is best, so they don't dry out.

I prefer to hand water as you know you are flushing everytime you water with fresh nutrients and sometimes drippers only get a small area and leave a bit of build up in the coco, it's a personal preference but thats my opinion.

Best of luck and theres plenty of people on here who Will help you out dude.

Try not watering so much, sounds like your drowning them, you can always keep an eye on the coco to see if it drys on top too fast. If your running 75% waste you need to reduce your input by 60% and remember the plants will thirst more the bigger they get, OK. Have Fun.

[Luke Skywalker]

If your electronic timer has an "alarm" function on it you should be able to set it for seconds, which particular timer do you have? Any chance of a picture?

 

btw, excessive runoff isn't necessarily a bad thing in a run to waste system provided it's not wasting too much nutrition and you're not overwatering the plants in the first place.

 

But yeah, get back to us on the timer model and I'll let you know if you can set it for seconds instead of minutes.

[cybergenesis]

Thanks my brother should be coming over in about 3-4 hours with his camera, I will take a picture and post it up then... Hang I'll just see if I can find the model:

 

"Nakajima Power ET-1"

 

Thanks for your response.

Edited April 29, 2010 by cybergenesis

[Luke Skywalker]

In that case I'm almost certain you can set it for seconds with some careful setting.

 

First, the programs don't operate on alarm like they do on auto setting. Instead of setting 1on for 8pm and 1off for 8.01pm, an alarm setting only requires you to set it on either on or off. So you could set 1on at 8pm and 1off at 10pm and it would water for the prescribed time on those programs. So in effect instead of 12 programs (12on and 12off) you have 24! (12on plus 12 on)

 

To set the period for the alarm setting, keep pressing program button until you get to the point where it just has two zeros, in the position that would otherwise be the "13th" program. This you can adjust by pressing the week/sec button to increase it from 0-59 seconds.

 

So as an example, I set the program for 1on at 8pm 1off at 10pm and 2on at midnight, then set the seconds on the "13th" program for 20 seconds. Instead of then setting the timer to "auto" you put it on "alarm". This is important, as if you set it to "auto" it will think you want it to run for 2 hours (1on 8pm 1off 10pm) and then run from midnight onwards constantly. If it's set for alarm though it will run for 20 seconds at 8pm, 10pm and midnight.

 

I hope that's helpful, the instructions in the manual that come with those timers are somewhat chinglishy I found but if you persevere with them you'll work out what it's saying. If you have any questions please feel free to ask.

[cybergenesis]

Thanks very much for that help- very useful. I will use the timer as the primary control for how much water they get.

 

Do you think 10%-20% is about the right amount of waste water to be getting? The water situation stays fairly consistent throughout the whole grow process from veg to flower?

Edited April 29, 2010 by cybergenesis

[bloodshot_eyes]

I run a run-to-waste coco sytem. 10% runoff is what I aim for. But with Coco, I find that its not too critical. If I'm not getting any runoff, I turn up my taps (which I have on every watering ring) and If I'm getting too much (like 30%) I turn them down. This has worked for me for a couple of grows now. So yes, in a run-to-waste system, 10%-20% is what you should aim for.

[The Hash Nibbler]

Thanks blood shot eyes, I was sure I had the run off % right. Just thought maybe if no-one talked to me maybe I am a figment of my own imagination??????

[cybergenesis]

Thanks everyone for the useful input- I think I have this just about figured out now

 

Luke Skywalker, I followed your outstanding instructions, they were easy to understand and clear. You really helped a lot with that info- thank you.

 

It seems like it all set, I will keep my eye on it, just to make sure, wouldn't want to come back and find out it has pumped the whole tank of water through the plants or something B) It would flood out because I only have a small container to collect waste water.

 

It seems to be producing at this stage around 75% waste water... Its a bit hard to tell, so what i do is take off the pipe from the pot, and collect the waste water directly into a container, because its hard to determine exactly how much waste you have when you have pipes filled with water etc

 

Now that I have set it for only 30 seconds, it should only get about 1 L of water, does that sound okay?

 

I had a disaster befall me, regarding my seedlings.. At the moment I only have 1 plant in the grow area, its 3.5 weeks or so into veg. However I am highly confident I should have 4 plants in there within 4 weeks, and another 4 plants in a 2nd grow chamber which is still yet to be constructed.

 

So here is a picture of my lone plant: :