Can someone explain to me how to top up a reservoir (rez)? I just don't get it...

[Aqua Man]

It gives you so much info you can see the cycles of how the plant increases and slows nutrient uptake. You can see if anything is going wrong with respiration or roots almost immediately before visable signs based on ppm changes and water uptake... I mean it just provides so many answers and assurances. It is more work but the info gained is irreplaceable

 

[Keesje]

Ok your full res is EC 1.2 the plants drink 10 gal and as such ideally that concentration is going to increase as the plants are drinking slight more water than taking up food so the EC increases as the plants drink... Say 1.3 now after they drink 10 gal. You add back a solution of 33% the EC drops back to 1.2 and you are pretty close to where ya wanna be.

Now I do understand your point of view and method. Thanks!


I visit a hydro greenhouse in my area now and then.
They can measure single elements in their (huge) reservoir.
So they do top off with water like we do, but they add single elements to get to the perfect balance of elements every day.

The big problem that we face (in recirculating systems) is that after just 1 feed, there is already an imbalance. And the imbalance will get bigger and bigger by the day. Just because roots absorb different elements at different quantities.
By topping of with RO water your imbalance will not disappear. Also you risk that your EC will go down.
By topping of with a 33%, 50% or 100% solution the imbalance will also not disappear. And the risk that your EC will get to high.
If 'repairing' the imbalance is your main goal, then there is no proof what will work better. The only proof that one could get, if you could measure every single element or send your water to a laboratory every day.
Perhaps there is a grower here that has the financial means to do this

 

[Aqua Man]

Now I do understand your point of view and method. Thanks!


I visit a hydro greenhouse in my area now and then.
They can measure single elements in their (huge) reservoir.
So they do top off with water like we do, but they add single elements to get to the perfect balance of elements every day.

The big problem that we face (in recirculating systems) is that after just 1 feed, there is already an imbalance. And the imbalance will get bigger and bigger by the day. Just because roots absorb different elements at different quantities.
By topping of with RO water your imbalance will not disappear. Also you risk that your EC will go down.
By topping of with a 33%, 50% or 100% solution the imbalance will also not disappear. And the risk that your EC will get to high.
If 'repairing' the imbalance is your main goal, then there is no proof what will work better. The only proof that one could get, if you could measure every single element or send your water to a laboratory every day.
Perhaps there is a grower here that has the financial means to do this

Much agreed that's why after adding back the volume of the system you change the water. This has been time tested and proven to work. Without adding back anything the ratio will change faster.

To give a simple example of why this works. If you look at planted tank aquariums most used what's called the EI (estimated index) method developed by Tom Barr. I won't get into all the shit as it's a never-ending topic much like hydro. They do 50% water changes weekly and replace the water with nutrients at 100% concentration. So what this does is limit how far the nutrient imbalance can get. You can google it and look at the math behind it rather than my lazy ass try to type it out. But basically by doing this weekly you can be guaranteed that you ratios stay withing in a certain percentage. The reason being for 50% is the preservation of bacterial populations. Now this is kind of how I do my system. I never change more than 50% of my water for the same reasons but I won't get into that. I have over 20years breeding fish and aquatic plants and testing specific nutrient levels much like the greenhouses you talk about but not quite on that level, so I have incorporated quite a bit of that into my system.

What I'm trying to say is that if you do a res change after adding back the volume of your system the nutrient ratios will not change enough to impact the plants.

 

[Aqua Man]

Now I do understand your point of view and method. Thanks!


I visit a hydro greenhouse in my area now and then.
They can measure single elements in their (huge) reservoir.
So they do top off with water like we do, but they add single elements to get to the perfect balance of elements every day.

The big problem that we face (in recirculating systems) is that after just 1 feed, there is already an imbalance. And the imbalance will get bigger and bigger by the day. Just because roots absorb different elements at different quantities.
By topping of with RO water your imbalance will not disappear. Also you risk that your EC will go down.
By topping of with a 33%, 50% or 100% solution the imbalance will also not disappear. And the risk that your EC will get to high.
If 'repairing' the imbalance is your main goal, then there is no proof what will work better. The only proof that one could get, if you could measure every single element or send your water to a laboratory every day.
Perhaps there is a grower here that has the financial means to do this

The amount of change a day will be directly related to the volume of the solution and the amount of uptake. So while it does change daily the amount of change differs based on those factors.

Also I would look at it as a small change in ratios as an imbalance would suggest the ratios are no longer adequate. If we look around we can see a large variety of ratios work.

 

[Keesje]

True.

The reply was more meant for people who claim that their system is the one and only right way.

 

[Aqua Man]

True.

The reply was more meant for people who claim that their system is the one and only right way.

Absolutely in growing there is generally never one right answer nor solution.

Eg. Changing nutrients every week also can work.

 

[SuperiorBuds]

What you call a 'side-effect' of the Torus Hydro (keeping the pH in check) is the main purpose of such a device, as I understand from their website.
In what way do you think it helps the EC of the nutrient as well?

Perhaps that wasn't worded clearly. I never said it did anything to the EC. I understand that keeping the pH in check is what it's meant for -- it's literally why I have it.

The side-effect is that because it's using ion-exchange instead of adding an acid or a base to the solution you can now keep the reservoir longer w/o dumping it. If you're adding pH up or down you NEED to flush the reservoir every week (or two at most) to get things back to neutral before you adjust.

 

[SnidleyBluntash]

Trial and error. If your pH is at 6.8 and you want to get it back to 5.8, just make a more concentrated top up solution. Once you do it so many times you will know how many squirts it takes change the pH.
Same thing with ppm. If you want to lower the ppm, use plain water.

 

[5BY5LEC]

Sorry if this has been said, but you are totally over complicating it.
Listen, get a one gallon jug and mix up a strong nutrient solution using the same ratio you normally use.
Fill your system up with water, then use the nutrient jug solution to get your PPM back to where you want. Adjust PH. Done.
Once you have added back the total volume of your system, change the water.

 

[Keesje]

You call some methods too complicated, and perhaps you are right.
But I am sorry to say that I do not understand your explanation as well

Listen, get a one gallon jug and mix up a strong nutrient solution using the same ratio you normally use.

What is a 'strong nutrient solution' when you say at the same time 'using the same ratio as you normally do'?
Strong for example is an ec of 2.4, but if my ratio normally is getting an EC of 1.0... what to do?
Or do you mean: Get a gallon jug, put in a gallon of water and mix in it the amount of nutrients that you normally would mix in your whole reservoir?
Or the amount of nutrients that you would need for the amount of water that is needed for the top off?
Perhaps you mean even something else?

Fill your system up with water, then use the nutrient jug solution to get your PPM back to where you want. Adjust PH. Done.

Why this extra step of the 'jug solution'?
Why not top your system off with water, and add nutrients until you get the PPM to where you want?

I am here to learn, so all info is welcome.

 

[Keesje]

Trial and error. If your pH is at 6.8 and you want to get it back to 5.8, just make a more concentrated top up solution. Once you do it so many times you will know how many squirts it takes change the pH.

Perhaps this works with your water and circumstances, but I am not sure if it will work in all situations.
pH is depending on several factors, not only the concentration of a solution.
Or did I misunderstand?

And if I add with a more concentrated top off, then there might be a chance that the EC will get too high.
How to avoid that with your method?

 

[Aqua Man]

Sorry if this has been said, but you are totally over complicating it.
Listen, get a one gallon jug and mix up a strong nutrient solution using the same ratio you normally use.
Fill your system up with water, then use the nutrient jug solution to get your PPM back to where you want. Adjust PH. Done.
Once you have added back the total volume of your system, change the water.

That's definitely easier but provides little to no info about the plants needs. Unless your gonna sit down and do the math but then you are just doing what I am a different way.

Im not saying the way I explained is the only or right way. It just provides some benefits that I feel can really help a grower understand the plants needs much better. It is more work but provides a window into the changes of your plants needs. Of course we can make it as simple or complex as we want I was just providing an option for those looking to up thier game

 

[fragileassassin]

I have a barrel that feeds into a float valve in my outside control res. I mix the barrel at the same strength as the system. 55 gallon barrel to a roughly 65 gallon system. When the barrel is empty, I let it run for a few days to see if anything goes up or down then do a 90% change and repeat.

 

[5BY5LEC]

Maybe it would have been better worded as "There are a lot of ways to add back, but none have to be complicated".
Keesje, let me explain. LOL I call strong solution 1.0EC or 500ppm.
So in my case I run 20 gallons. At this point I use (ml) 20 Calmag/ 20 Micro/40 bloom for that entire 20 gallons to get me to around 400ppm.(.8EC) A general "week 7 flower" mix.
So in a one gallon jug I would use that same ratio just maybe less, in other words I would use 10/10/20 for that one gallon jug.
I mix said jug up and keep it next to my res, or in the fridge if it is summertime. I add water to the res, and then use the one gallon jug with the "hot mix" to get the PPM back up, since ppm will have dropped with adding water.

 

[5BY5LEC]

I have a barrel that feeds into a float valve in my outside control res. I mix the barrel at the same strength as the system. 55 gallon barrel to a roughly 65 gallon system. When the barrel is empty, I let it run for a few days to see if anything goes up or down then do a 90% change and repeat.

This would actually be the best way to do it. Have the top off hold whatever the maximum amount of water the plants will use until next res change.
Literally mix the top off and let IT do the work keeping your stuff in check during the week.

 

[SnidleyBluntash]

I have a barrel that feeds into a float valve in my outside control res. I mix the barrel at the same strength as the system. 55 gallon barrel to a roughly 65 gallon system. When the barrel is empty, I let it run for a few days to see if anything goes up or down then do a 90% change and repeat

do you worry about the external rez “going bad” over time? Some claims say to use the product right away after being made and not let them sit. I imagine some living organism products this could matter for, and maybe some chemical reactions occurs to reach equilibrium, but would just nute salts ‘go bad’ in solution? I don’t think so.

 

[fragileassassin]

do you worry about the external rez “going bad” over time? Some claims say to use the product right away after being made and not let them sit. I imagine some living organism products this could matter for, and maybe some chemical reactions occurs to reach equilibrium, but would just nute salts ‘go bad’ in solution? I don’t think so.

I use megacrop, they said you can mix and store it for a pretty long time. I dont remember how long it was, but wayy longer than it sits for me, and this is one of the reasons I use it. I have a pump in the barrel on a timer that pumps it up to the top to mix it for 15 mins every few hours. I add my southern ag fungicide to it just like I do the system. Painted the barrel so no light gets in it and it sits on 2 concrete blocks on the basement floor and that keeps it cool enough.
I just cut the system in half. It was previously 12 sites and around 130 gallons total. It emptied a full 55 gallon barrel as fast as 4 days. At that rate I'd run 3-4 barrels between changes.

 

[Dro3420]

Sorry if this has been gone over, if so please direct me to the information! I am having some trouble wrapping my head around the concept of refilling a reservoir that still has nutrient solution in it. I'm specifically referring to flood/drain ebb/flow, but any recirculating rez would apply.

Let's say for example (I made these numbers up from recent experience), I add 20 gal of RO water @ 6.8pH and 10ppm, I add 5ml per gal of MagiCal, bringing the ppm to 260. Then I add veg nutes, upping the water to 850ppm. The pH has now gone down to like 4.5pH, so I add pH Up til it's at 5.6pH, the water is now 900ppm. I feed the ladies, afterwards the rez is low, they were thirsty.

Now I want to refill it, but (unlike I currently do), I don't want to empty the remaining solution. I cannot figure out how anyone is calculating their nute solution if you add more than one liquid to your rez, which I'm guess most people are doing.

So now I check the rez, say it's 6pH and 930ppm now. I add water to the rez, filling it back up to 20 gal. Now I check the pH and ppm, the ppm is now like 230ppm, like 6.4pH.

Of what is this 230ppm comprised? How can I possibly calculate the ratio of MagiCal I should leave out to compensate for the bit that remains in the rez from the original rez dosing? I want to have 250ppms of Calcium, Magnesium, and Iron from the MagiCal, how can I measure this if the solution has been diluted?

Please enlighten me as to how anyone and everyone are topping up their reservoirs. I'm guessing it's a simple thing I've over looked.

There is no way to tell precisely how much of what nutrient is left.

 

[Dro3420]

There is no way to tell precisely how much of what nutrient is left.

U just add what ur missing. If 1/4 of ur rez in empty add 1/4 water with 1/4 strength nutes. Then every 7 to 10 days change out completely

 

[Dustuballz]

If my ec reeding is going up I add plain ph water if my ec level is staying the same as the water level drops this I let the plants drink until the next res change I change my res every 2 weeks and it's a 55 gallon tank.