Thanks! I've been growing hydroponically off and on since my college days in the early 80's (dating myself). Though I have been involved in larger-scale ops in the past, I only grow for personal legal MMJ use now. This will be my 6th grow using a 250 watt light, each one has yielded progressively more as I try new things...
Thank you!
Thanks, man! It really wasn't that hard to build, just measure twice and cut once LOL! I enjoy DIY, though, so it isn't a chore!
OK, you say "I am going to be experimenting with fewer res changes myself with my new diy setup...but Im not sure about how this would effect the benefical bacterias in the system as in would it let them build up to a harmful measure." I don't believe this is a problem you need to worry about, the beneficial bacteria building up is a good thing - this is called "aging" the water.
In fact this is probably the reason I can run the system so long with lower-level nutes between res changes - the beneficial and symbiotic bacteria/fungi that have built up in my res are keeping the water clean AND allowing the roots to take up ALL of the nutrients.
All frequent water changes and reservoir cleanings do is make this "aging" process start over again! If you've ever maintained a large-scale aquarium (I've done reef tanks) you'll understand that you want the beneficials to build up and that you never do a full water change or thoroughly clean the system (unless something is seriously wrong). You want the water to achieve a balanced condition and this takes time; if you do a full water change and kill off the beneficials you have to start building them up all over again to achieve a balance.
If you monitor your pH you'll probably notice that when you first start up the system and add water the pH will usually move around, usually up. If you leave the pH pretty much alone, then within a few days it should start to stabilize - this is an indication that the beneficials are starting to build up. Once the pH has stabilized your water is pretty much balanced and you should never have to worry about pH again.
But time and time again I see newbies chasing the pH, trying to maintain some "optimal" level only to shock the plant, leaving the plant vulnerable to attack from pathogens. And every time you do a full res change/cleaning you have to start this process all over again, leaving the plant open to attack.
Notice I haven't said anything about organic nutrients yet. In my opinion, there are basically two ways you can maintain your water to insure that pathogens don't take over: maintain water conditions that the beneficials thrive in, or sterilize the water so nothing (except roots) can grow in there.
Beneficials love cold water with lots of dissolved oxygen (DO). If you can maintain your water below 70* F then you should have NO PROBLEM attracting and maintaining the benficials REGARDLESS of whether you are using organic or chemical nutrients. The beneficials will keep the water clean and all frequent water changes will do is upset the balance. If you must change the water, then only change one quarter of it at a time.
Nasties love higher water temp with low DO. If you CANNOT maintain low temp/high DO water conditions then in my opinion you should maintain STERILE water (with something like a preventative H2O2 regimen) and ONLY use CHEMICAL nutrients. While organics do attract and feed beneficials (the beneficials are, in fact, necessary for organics to work) they will ALSO attract and feed the nasties IF the water conditions are conducive to the nasties growth. So in poor water conditions I would use chemical nutes only and I would also use H2O2 and do frequent water changes and cleanings to maintain sterile water.
So in short, yes you can grow with few or even no water changes - it is even BETTER if you do, IMO - IF your water conditions are conducive to beneficials. If not, then I would recommend using only chemical nutes and maintaining sterile water with frequent water changes.