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When to change your water!

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Time for a change?


How often should you change your nutrient solution? That's one of the most common questions asked, and one of the most difficult to answer. Many people have tried to come up with a simple, easy-to-follow rule - once a week, every two weeks - but they're all wrong! They're wrong because there is no simple answer. It all depends on the species, the number and size of your plants. the capacity of the reservoir, the kind and quality of nutrient you use, water quality, environmental conditions such as temperature and humidity, and the type of hydroponic system used. Instead of a simple answer, what we need is a procedure that takes many of these variables into account and is responsive to changing conditions.




It sounds complicated, but it's actually quite simple. All it takes is a little monitoring and some basic record keeping. Start with a fresh reservoir of nutrient and make note of the date, pH, and EC or PPM of the solution. As you run the system, the level will drop in the reservoir. Note the EC/PPM level, then top-up the reservoir with fresh water. Test again for nutrient concentration. If the nutrient strength has dropped significantly, add a bit of nutrient to bring it back up to specs.




Be sure to record how much water you added to top-up the reservoir. Repeat the procedure every time you top up the system, carefully recording the amount of water added. When the total amount of water added equals the capacity of your reservoir. it is time to drain and replace all of the nutrient solution.




For example, imagine a hydroponic system in a cool, spring greenhouse with 24 strawberry plants and a nutrient capacity of 20 gallons. Typically, such a system would require about 5 gallons of added water each week, After four weeks the plants will have transpired 20 gallons - the capacity of the reservoir. You need to completely drain and replace the nutrient every four weeks in this example.

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I flush&change nutrients around every two weeks; based apon the water color (and recommendations by my local hydro-shop-man according to my setup).

When my reservoir has a fresh tank of nutrients I take note of the water color, after two weeks it still has some color, but not much, which brings me to believe there is not enough good stuff left in the water....maybe not THE most accurate method, but my plants dont seem to mind lol

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The reason I printed the above text was because there was never any accurate way of knowing when the best time for a water change is (too many variables) but im going to try the above method and see if it increases yeild and saves nutrient, time and money. But it makes alot of sence in my head.



Ok ----> Swing has tried many different combinations varying from changing every feed, every day, every week, ever second week to never changing at all.


Swing has made a number of conclusions which are as follows:-


1)Rapid growth and yeild beyond belief when you chance it every day or every feed, using a run to waste setup, but takes a lot of time (which swing does not have) and money for nutrient.


2)Every week ---->Seems to maximinse growth and yeild and still not spending unrealistic time and money on setup.


3)Every second ----->Lower yeilds per plant about 1/2 oz on average, seems to be not as vigorous looking, as above plants.


4)Never change-----> same as every second week.

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hey guys , this made for intresting readin so i thought i'd add my 2 cents worth .

i have never changed my solution until it's time to switch from veg to flowering , i monitor nutriant level daily . my nutriant tank holds 40lt water. i dose the tank with either water or nutriant according to the cf reading . cf = 18 for veg and 24 for flowering . the water is held at constant temp of around 24 deg cent with the aid of fish tank heater . i also found that light encourages algy growth in the water so try to keep tank covered . all water added is also filtered prior and i also use an inline filter on the feed line to the gully's . i havn't had any loss in yeild or growth , but i guess each to there own and sometimes water availability is hard ( i fill 4lt bottles ) . ow i forgot to mention that i drain tank completly before changing over the nutriant mix . sorry if i bored ya , just sharing what i've learnt.

spot ya all L8tr

bushy :D

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Guest elefunk_delivers

I change my water weekly.. and ive always notice a rapid kick in growth 3 days later..

im happy changing weekly and i think its the go for all growers

using a ressi..


hope this helps


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what about a filter that takes all the nutrient/salts out of the water? You could set this system to run every week and dump the cleaned water in a holding tank and periodically you just mix some nutes and add top up water to it and throw it back in your main res. Would reduce the amount of water you needed and eliminate the need to drain and dispose of water every flush. I have to carry all water to and from my grow room in buckets and its a PITA.
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