how important is changing the res weekly

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I went two weeks when I first put my plants in my system. Now that they are 15 inches they suck up nutes to fast, and I am not sure what is left over in the solution so I will be changing every week now till they are done. My PPM's drop from 800 to 450 over night.
 
I must agree with Tater on the fact that if you follow a set pattern you are sure that the plant is getting everything it can to promote the best results! But even if you are checking your ppm regularly you will see that a small young hydro plants impact on the nutes is small, so I guess the whole changing nutes weekly question comes down to the amount of nutes absorbed by the plant at a certain stage in growth while still giving your plant everything it needs so abundantly and easy to absorb that all its energy is spent producing huge healthy buds. Makes me wonder how different my expiriment plant would look right now with a regular water change? I should have ran plants side by side for a proper expirament.... DOH" I feel like homer simpson.... ALTHOUGH having done this once or twice before, it is not at all unhealthy or puny. No MJ plants were harmed in this expiriment!
:rolleyes:
 
I change my res every 2 weeks while in flower.....I grow one plant per 5 gal bucket in a DWC. Use about 4.25 Gallons of water to mix the Nutes....Using a combination of Botanicare Pro blend grow and bloom, Liquid Karma, Hydroguard, Cal-Mag and Fox Farms Big Bloom.... I am still trying to dial in this girl i been growing for a few grows... she is getting better though. I will add water every week though if there is a large amount of usage or evapoation.

For Vegging my clones (usually about 4 weeks, so I can make sure I fill my bloomers in case I have a major Clone failure). I use the same water all the way through... Only Nute it once and just add more water if needed.
 
Just found out why I should be changing every week. The plants absorb certain nutrients quicker then others. So if you are topping off you res with more nutes and water it will lead to excess build up of certain nutes, minerals, and salt. This makes complete sense to me so for now on it is every 7 days. This could have lead to some of the deficiencies and nute lockouts I was getting.
 
That is a very good point, and even though when I top off my res I use only straight well water with no nutes added so I dont overdo and burn plants I do not want to lock the plant up. But ya' know how it is after growing awhile you get itchy to expiriment every couple grows and I am fairly new to hydro long time dirt farmer... fun to expiriment especially when it benefits my antianxietystressrelievinrelaxtime medicine.

actually, I am worried now that buddylove might be right about nutrient lockout and wonder if I wont see signs in future from my not changing nutes in the past... I do have a few curled leaves but look like nute burn from finally changing the res... I changed at 1/2 dose technaflora recipe for success into 4 gal res????
 
Now that I think of it I probably shouldve done 1/4 dose nutes since I deprived the plant for so long... however looks deep green and a true beaut with just a few curled leaves standing @2foot tall or so. I think even 1/2 dose was too much from the watered down mix it was in... Nothin' life threatenin' or nothing but I get fond of my plants especially now that its my "special" plant!
 
Yeah I think it is best know to just top off my res after every change with just ph'ed RO water. Even if the PPM in the res drops below what you want that doesn't mean you have none in the root structure or medium. I am flushing my system tonight with distilled water to see what the run of is ppm wise. The distilled had a PPM of 20-22, depending on the jug. I put 14 gallons in and emptied and cleaned res. Lights went out for the first time tonight and I will be starting my bloom nutes tom, so I figured what the hell can't hurt em. I will see what the PPM in the water is like tommorrow. That will give me an idea of what kind of nute, salt and mineral build up I get in my system. Plus I just realized after talking to the guy at advanced that the way I was doing it my plants were getting the equivilent of 1800 ppm a week. Ouch know wonder I was having a few small issues.
 
Tater said:
Another concern that raised up in a separate conversation I had with another grower in my area was that different plants at different stages use nutrients at different levels. Some use more N and later in their life use more P and K but how do you know how much they are using. Changing your rez every week allows you to re balance the nutrient solution so to say. PPM's won't tell you if your solution is low on nitrogen ;p just something to think about.

wats this PPm is it a meter that gives u reading on ur nutrient level?
is this needed in doin hydro ?
and where u get one if any? or wats the correct term for it if i go to a hydro store to ask for it
 
UPDATE:

I know its been awhile since posting this, but yesterday, I had to destroy this plant... darn thing grew balls on me! So many males this year! Turned out to be a beautiful plant too, complete waste of a good big rockwool cube!


All in all it was a fun expiriment, I do think since I am starting a new batch of seeds that I will do a two week water change on seedlings through a foot tall plant in the future, I know that I can stretch that now from this little test but I worry about any stress that could possibly effect the health of future buds (or in this case balls). Nutrient lockout and fluctuating PH are another concern for stretching nutes. Since in essence with hydroponics you are giving the plant EVERYTHING it needs and allowing the plant to be a super lazy couch potato and just suck up nutes and grow while manipulating the light it receives both in intensity, color spectrum and time... what more do we really need for a lab expiriment!

Cheers All
 
zipflip said:
wats this PPm is it a meter that gives u reading on ur nutrient level?
is this needed in doin hydro ?
and where u get one if any? or wats the correct term for it if i go to a hydro store to ask for it

With hydro number one test IMHO would be PH so you need and probably already know and are doing so.:) To test the PPM (parts per million) it is a reading of the dissolved organic and inorganic matter suspended in the water. If you use plain tap water there are already present organics dissolved in the water even if your plant will not use any of it. If you use RO water you start with a stripped water and a neutral base PH. Any nutrients you add will add to the water a reading of dissolved solids present in the water (This is correct right guys? Many users way more advanced than me in this stuff!). A TDS (total dissolved solids) meter will measure the amount of like it says total dissolved solids. However you can also measure EC (electric conductivity) since nutes are made up of salts and tell you like TDS when to add nutes or dilute. You can get many models at your local gro shop or even at stores like Lowes I have seen them.

Best of luck
The more you know, the more ya grow!

:smoke1:
 
:watchplant: I did several generations of SnowWhite and NEVER never CHANGED THE RES, I did add nutes and water to keep ppm and ph the same thruout. worked fine for about 18 months and then I messed up the ratios and had to dump res and reconfigure :farm:
 
I change my rez every week. But I bet if you had a full time ppm meter in there and watched it you might be able to go 2 weeks at a young age. Thing to remember is that as the plants use water and the water evaporates the solution is going to get stronger and can end up burning your plants. Plus the longer the water sits the higher the risk of disease and algae and a host of other problems. But if you were careful I don't see why you would ever have to change your water it would be a matter of stopping algae growth and disease and monitoring the strength of the solution and adapting the formula as necessary. I think it would be a lot of work.[/quote]
It can be a lot of work to change your res every week, I know of an easy way to do it though...and it keeps you from ever having to scrub your res or ever having a build up problem. www.GARDENARMOR.com

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How often would you change the nutrient solution in a 35 gallon res with 4 plants in 5.5 pots? What level would you have the solution at? 10 gallons maybe?
 
it would depend on if you were flooding on using drip
 
Number one if you are going to use my posts please quote me.
Number two when I said it would be a lot of work I was referring to trying to control algae and disease in your tub, not changing the water and keeping it clean.
 
i just started dwc in 5 gal buckets and i check my ph and tds daily.there is a definite drift between strains and plant health.i started all out on 1/8 dose using the lucas formula.grow and micro.GH products. and i adjust my res on each plant almost daily.either ph will start drifting,usually higher due to the need of more nutes.it surely differs with the strain of the plant.
i have not changed my res on the young ones for 3 weeks.i just keep a close watch on them.the gh does have a tendency for salt build-up.
 

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