How low is too low? DWC water levels.
Posted 22 April 2012 - 09:13 AM
What I'm wondering is.. How low can the water level go? I'm using 20 litre buckets. I have read that some people like to leave more of the roots in the air as a grow continues and others that just like 1 inch below till harvest.
Any of you DWC experts out there use lower water levels or should I just keep 1 inch below pot till the end?
At a guess I would presume that as long as the "bursting" bubbles throw up the damp mist to keep all roots on display stay damp/moist then the water level is fine. So a certain degree of "how good is your air pump" and "how good/big are your airstones" will come into this. correct?
Posted 22 April 2012 - 09:16 AM
11oz 1plant 400w scrog
jiffs scrog guide
Posted 01 May 2012 - 12:07 PM
You are correct about the airstone and pump making a difference. Think about how much airflow you need and then double it. I have also found the 9" disk ceramic stones to be very good for the 20 L bucket. Gives a good misting all over the root ball even when the water level is below the bottom of the net pot. I pretend in my own little way I have created aeroponics
I have also filled up to literally the top of the baskets with no measurable effect when going away for a few days. My girls drink 4 to 5 L a day though so your mileage may vary.
My understanding that a mixture of depths is probably the best for your plants. If you look at how the other hydro systems operate then they all do something similar. Also shouldn't your recirculating system drain out the water periodically from the pots back to the central reservoir? I'm not sure how much option your timer/brain gives you over the circuit but the one I looked at it was pish.
Haven't heard to much good things about the recirculating systems. I ordered one into my favourite shop but after taking a look at it decided to stick with filling up myself. I do a complete water change every 5 to 6 days and throw out all the waste, saves faffing about with pH as I mix the reservoir all up to the same.
I agree with jiffa - drip feeding until the roots are coming out of the baskets or even longer is a good way to go. Don't stress to much about it though. DWC is pretty bulletproof!
Posted 02 May 2012 - 02:57 AM
Some systems drain back to the main res but most (including mine) just use the main res to top up the controller pot via ball/valve and only recirculate back to the controller bucket. This gives very stable EC and PH levels throughout the grow and is the reason i choose to grow this way. It is like you said, Bulletproof. I just fill the 100 litre res up with fresh nutes every 10-14 days and that's it. The system of pots just takes what it needs when the water level drops to my desired level. This said, it does come with it's drawbacks. Like constant noisy air pumps 24/7 (there is no such thing as a quiet one iv'e discovered) The worry of pump failure also isn't good. and there is always a risk of flooding with a faulty ballcock or roots/clay pebble blocks your return line in a bucket. I bought a wireless moisture alarm to help ease my flooding worries though. Sharing the same nutes doesn't lend itself to mix 'n' match growing either. you really need to grow the same strain in all the pots.
These things are outweighed when you see the results.
My little bottle bubble cloner which works a treat. No need for rockwool, lighting, humidity, propagators, heat mats or cloning gel etc. Just snip a few off and plonk them in the bottle and leave for a week.
in about 30 days! is why i like the DWC bubblers
What's often overlooked as a plus point for recirculating systems is just how well you know your nutes are always going to get mixed up. I think a lot of people suffer problems from nutes that are poorly introduced to their systems and causing lock ups and lock outs. Adding liquid silica for example iv'e found can be a tricky job to do well in some hydro systems. not in this one.
I'll keep what you said in mind and won't worry at all about different levels making a difference now. Thanks
This post has been edited by Owderb: 02 May 2012 - 08:11 AM
Reason for edit: To remove hosted pics. Please upload to here
Posted 02 May 2012 - 06:18 PM
You don't need a huge amount of oxygen in the liquid as long as the oxygen keeps getting replaced. What gives the rapid growth ime is the rapid churning of the liquid. This forces fresh nutes through the root mass to give the same effect as nft. You'll notice that all systems that have a high volume of nutes going through the root mass give rapid growth.
I ended up sacking the airstones and replaced them with a Tee, the airline got duct taped to the bucket and never any more worries about clogged air stones. Top of the liquid looked like a piranha feeding frenzy.
Can't have too much air*. If I were going to do bubblers again, I'd use a decent sized Koi pond pump.
e2a: * more air for the churning effect.
This post has been edited by lazi: 02 May 2012 - 06:20 PM
Posted 02 May 2012 - 08:24 PM
I'll try my current grow with high water levels and see how it goes Lazi. Thanks.
I did try and post the images using the sites image host in my previous post Owderb but all my photos are bigger than 300kb which isnt allowed it seems. :/
This post has been edited by Defunkt: 02 May 2012 - 08:26 PM
Posted 03 May 2012 - 12:42 PM
What might interest you is swc, shallow water culture. Only noise from that is water falling 18" into a res. (afaik, that's the min drop to kill bacteria and aerate the liquid.) keef treez was getting 2oz psf from his grow tunnels using 3 x 400w in an 8' x 4'. Amazing considering hps lights back then were not a patch on todays hps.
He did an 8' x 4' tray, pond liner effort and a good sized water pump blasted all 4 corners of the tray. In the middle was a 4" hole with a 2" high rim so always 2" of water in the tray. I can remember most of the build details if you're interested.
Posted 16 May 2012 - 04:07 PM
Instead of air stones I use an external fish tank filter with a spray bar that runs the length of the resevoir and is constantly squirting water and breaking the surface tension.I add beneficial bacteria (GH subculture) to the extranal fish tank filter.
my diary tries to explain it