Why change water in hydro system?

JonCreighton

Well-Known Member
Im setting up the hydro system and im kind of confused why my friends change out the water in their systems.... i tried to get an explanation but couldnt understand

based on this paper it seems not that difficult to not have to drain and refill... 284231562_Nutrient_management_in_recirculating_hydroponic_culture

incase anyone wondering.... this is a ruffestimate what i got form the paper in terms of start/target and replacement nuits on the right side of the spreadsheets
 

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ҖҗlegilizeitҗҖ

Well-Known Member
Im setting up the hydro system and im kind of confused why my friends change out the water in their systems.... i tried to get an explanation but couldnt understand

based on this paper it seems not that difficult to not have to drain and refill... 284231562_Nutrient_management_in_recirculating_hydroponic_culture

incase anyone wondering.... this is a ruffestimate what i got form the paper in terms of start/target and replacement nuits on the right side of the spreadsheets
From Current Culture, a leader in RDWC technologies, "Regular change outs ensure plants receive balanced nutrition. It is recommended to perform a full nutrient change out every 7-14 days. This will ensure nutrients are fresh and viable, while also correcting any imbalances to the nutrient solution."
 

myke

Well-Known Member
Coco is hydro,fresh nutes sometimes 3 times a day.Rdwc same nutes with fresh top ups weekly never completely draining except when light cycle change. 2 plants side by each.one coco one rdwc......Which one grows bigger?

In my bsmt,rdwc will win.
 

TintEastwood

Well-Known Member
This applies to dwc also.

"Nutrient levels and nutrient balance
The amount of nutrient and the nutrients balance are difficult to watch on a day-to-day basis. If you are using a well-balanced nutrient solution and a more regular short & frequent feeding regime, then there is less chance that the plant will run out of a particular element because the complete balance of elements is continually being supplied. Knowing the level of nutrient is relatively easy by taking an EC reading (EC just measures the amount of salt). To know the actual balance of the nutrient in the media you would need a lab analysis of the media which is obviously not going to happen for most growers."


One way to think of it...

We serve up the full array of food (nutrients) to the plants.

But the plants only consume what they can consume.

The food (nutrients) not consumed are 'leftovers' that remain in the media. Res water in the case of dwc.

Topoff. Mixing new nutes, with leftovers can lead to imbalances.
 

ҖҗlegilizeitҗҖ

Well-Known Member
This applies to dwc also.

"Nutrient levels and nutrient balance
The amount of nutrient and the nutrients balance are difficult to watch on a day-to-day basis. If you are using a well-balanced nutrient solution and a more regular short & frequent feeding regime, then there is less chance that the plant will run out of a particular element because the complete balance of elements is continually being supplied. Knowing the level of nutrient is relatively easy by taking an EC reading (EC just measures the amount of salt). To know the actual balance of the nutrient in the media you would need a lab analysis of the media which is obviously not going to happen for most growers."


One way to think of it...

We serve up the full array of food (nutrients) to the plants.

But the plants only consume what they can consume.

The food (nutrients) not consumed are 'leftovers' that remain in the media. Res water in the case of dwc.

Topoff. Mixing new nutes, with leftovers can lead to imbalances.
Very good explanation
 

myke

Well-Known Member
I use to run a high EC in rdwc,then I changed it to half so 1 EC.Changed nutes every week.Now I just top up,still feed low 1EC max.
I dont see a difference.
Only thing I do is mix less of part 2 of my nutes,less N otherwise.
 

JonCreighton

Well-Known Member
This applies to dwc also.

"Nutrient levels and nutrient balance
The amount of nutrient and the nutrients balance are difficult to watch on a day-to-day basis. If you are using a well-balanced nutrient solution and a more regular short & frequent feeding regime, then there is less chance that the plant will run out of a particular element because the complete balance of elements is continually being supplied. Knowing the level of nutrient is relatively easy by taking an EC reading (EC just measures the amount of salt). To know the actual balance of the nutrient in the media you would need a lab analysis of the media which is obviously not going to happen for most growers."


One way to think of it...

We serve up the full array of food (nutrients) to the plants.

But the plants only consume what they can consume.

The food (nutrients) not consumed are 'leftovers' that remain in the media. Res water in the case of dwc.

Topoff. Mixing new nutes, with leftovers can lead to imbalances.
I get what ur saying... the article i posted has rather simple instructions on how to determine what ur nuitrient content should be... and on what is being taken out by the plant and at what time.... therefore it seems rather simple to just put back what is being taken... my understanding was this is a huge part of why hydroponics was used in the first place.. resources..

so my question is assuming nuitrient balance and content goes well... is there any other reason?? disease? root discharge? idk...

what i was trying to show w the spreadhseet was if u look at what my estimate are of what weed plants are taking out based on that paper... its basically the same thing the whole time lol...

i think this is why u always hear bugbee saying 1.3 and 20-10-20 straight thru... that paper i think is his some of the reasonning their...
 

JonCreighton

Well-Known Member
Coco is hydro,fresh nutes sometimes 3 times a day.Rdwc same nutes with fresh top ups weekly never completely draining except when light cycle change. 2 plants side by each.one coco one rdwc......Which one grows bigger?

In my bsmt,rdwc will win.
ya basically kinda the same... well have runoffs from those mediums tho... my understanding was this is nessesary? thats kinda what concerns me here w the dwc
 

Wastei

Well-Known Member
So here we go again. You come here for advices but have already made up your mind?

It's not insanity when practically everyone follow the same practices and guidelines. I guess you have tried both changing out weekly and say monthly then?

Calling something insane without having any clue or personal experience to why is dumbfounded and insane if anything.
 
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dbz

Well-Known Member
I get what ur saying... the article i posted has rather simple instructions on how to determine what ur nuitrient content should be... and on what is being taken out by the plant and at what time.... therefore it seems rather simple to just put back what is being taken... my understanding was this is a huge part of why hydroponics was used in the first place.. resources..

so my question is assuming nuitrient balance and content goes well... is there any other reason?? disease? root discharge? idk...

what i was trying to show w the spreadhseet was if u look at what my estimate are of what weed plants are taking out based on that paper... its basically the same thing the whole time lol...

i think this is why u always hear bugbee saying 1.3 and 20-10-20 straight thru... that paper i think is his some of the reasonning their...
Bugbee has an array of lab equipment at his disposal, trying to grow exactly how he does is not the way to go unless you have hundreds of thousands to spend on all the lab equipment to constantly analyze everything and grad student slaves to do it for you.

Cherry pies, blackberry pies and apple pies. There are 10 pie eaters and 10 slices to each pie. However right now they prefer cherry and every day they eat all 10 slices of the cherry and split 2 slices of blackberry and 2 slices of apple. Every day though you bring a new pie of each kind. Very soon you will have no cherry every day but tons of leftover apple and blackberry pie.
In plants too much of a nutrient can be just as detrimental as not enough and cause lock outs and a plethora of problems. Of course if you have grad students and a full lab to analyze exactly what was eaten every day then you can replace according to need.
I love Dr Bugbee, but he also has all of this stuff at his disposal we don't. If you do have it, then well why even be here in the first place and I'm jealous.
 

Hollatchaboy

Well-Known Member
I can say this from my experience..... as the plant is taking up nutes... the pH buffers in those nutes decreases. When I made a fresh solution with the Lucas formula, it would come to 5.5 ph. I would let the water level drop a gallon and let the ph rise to 6.2. Then the ph would drop again. I added back plain ro water and it would bring it back to 5.5. After 2 days of that the ph was uncontrollable. I don't see how topping off would keep the ph in check without adding a shit ton of ph up and or down.
 

Hollatchaboy

Well-Known Member
I can say this from my experience..... as the plant is taking up nutes... the pH buffers in those nutes decreases. When I made a fresh solution with the Lucas formula, it would come to 5.5 ph. I would let the water level drop a gallon and let the ph rise to 6.2. Then the ph would drop again. I added back plain ro water and it would bring it back to 5.5. After 2 days of that the ph was uncontrollable. I don't see how topping off would keep the ph in check without adding a shit ton of ph up and or down.
 

Hollatchaboy

Well-Known Member
Bugbee has an array of lab equipment at his disposal, trying to grow exactly how he does is not the way to go unless you have hundreds of thousands to spend on all the lab equipment to constantly analyze everything and grad student slaves to do it for you.

Cherry pies, blackberry pies and apple pies. There are 10 pie eaters and 10 slices to each pie. However right now they prefer cherry and every day they eat all 10 slices of the cherry and split 2 slices of blackberry and 2 slices of apple. Every day though you bring a new pie of each kind. Very soon you will have no cherry every day but tons of leftover apple and blackberry pie.
In plants too much of a nutrient can be just as detrimental as not enough and cause lock outs and a plethora of problems. Of course if you have grad students and a full lab to analyze exactly what was eaten every day then you can replace according to need.
I love Dr Bugbee, but he also has all of this stuff at his disposal we don't. If you do have it, then well why even be here in the first place and I'm jealous.
If he has that equipment, why is he asking? :p :bigjoint:
 

myke

Well-Known Member
I can say this from my experience..... as the plant is taking up nutes... the pH buffers in those nutes decreases. When I made a fresh solution with the Lucas formula, it would come to 5.5 ph. I would let the water level drop a gallon and let the ph rise to 6.2. Then the ph would drop again. I added back plain ro water and it would bring it back to 5.5. After 2 days of that the ph was uncontrollable. I don't see how topping off would keep the ph in check without adding a shit ton of ph up and or down.
How does adding plain RO water bring pH down?
 

myke

Well-Known Member
There are some growers here in coco that don't feed to runoff.
I feed my coco sometimes with my rdwc res water,in a hurry no time to mix.
Would be a good experiment,feed a coco plant only rdwc water thats 1 month old.
 
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