Why do people cut back on feedings at night with hydro?

[PetFlora]

My roots grow into polished ornamental stones, which don't hold the solution, but keep th roots cool and moist. If I had a chiller I could flood more often than I do during the day, which is every HOUR

 

[Johnny Lawrence]

Your posts border on stupidity.

What is it about your ornamental stones that keep the roots so cool? I didn't realize different rocks maintained the root zone at different temps.

Perhaps a thread should be started to release this information?

 

[ttystikk]

Your posts border on stupidity.

What is it about your ornamental stones that keep the roots so cool? I didn't realize different rocks maintained the root zone at different temps.

Perhaps a thread should be started to release this information?

Saved me the trouble of saying it.

I've found that well designed waterfalls in the tubsites allow one to run RDWC without water chilling.

I think that's news peeps can use.

 

[Keesje]

If you look at commercial hydro-greenhouses, they do not use chillers at all.
Just a side comment and in no way intended to state that one should not keep his reservoirs cool.

 

[ttystikk]

If you look at commercial hydro-greenhouses, they do not use chillers at all.
Just a side comment and in no way intended to state that one should not keep his reservoirs cool.

Commercial facilities don't use RDWC or DWC. They use coco or rockwool run to waste, flood and drain and standing water systems, none of which are oxygenated.

 

[Keesje]

An additon...

I visited several commercial greenhouses that grow plants, herbs, vegetables on hydrosytems.
What struck me most are the following things.
- They do not care that much if roots are a bit exposed to light. So you sometimes see green stuff floating in the bassin.
- They do not care that much about the heat. If it becomes warmer for a couple of weeks, so be it.
- They oxygenate their water hardly, or in a strong way. For example just switching on a circulationpump for 5 minutes per hour in a huge bassin. Some systems use a venturi or have a constant flow of the water.
- They do not work that clean. They lift up the plants, touch the roots with their hands, walk in the reservoir with rubber boots that are not really clean.
Just some observations.

 

[ttystikk]

An additon...

I visited several commercial greenhouses that grow plants, herbs, vegetables on hydrosytems.
What struck me most are the following things.
- They do not care that much if roots are a bit exposed to light. So you sometimes see green stuff floating in the bassin.
- They do not care that much about the heat. If it becomes warmer for a couple of weeks, so be it.
- They oxygenate their water hardly, or in a strong way. For example just switching on a circulationpump for 5 minutes per hour in a huge bassin. Some systems use a venturi or have a constant flow of the water.
- They do not work that clean. They lift up the plants, touch the roots with their hands, walk in the reservoir with rubber boots that are not really clean.
Just some observations.

These are indications that the systems they use are robust, that is to say fault tolerant. This may be the single most important specification for a hydro system; if the damned thing is so finicky that it will crash and kill all the plants if things aren't carefully kept 'just so', then frankly it isn't any good.

Dependability is key.

 

[PetFlora]

Many here seem to assume that all ambient room temps are within reasonable tolerances. My room would easily stay in the mid 90*s if I didn't run the ac at ~ 85*s.

That means my rez water would too. Now you all may think very arm water would not affect the roots, BUT, the warmer the water, the less oxygen it holds...

It's because of all the stupid assumptions that I stopped posting threads in RIU

Have a nice day

 

[ttystikk]

Many here seem to assume that all ambient room temps are within reasonable tolerances. My room would easily stay in the mid 90*s if I didn't run the ac at ~ 85*s.

That means my rez water would too. Now you all may think very arm water would not affect the roots, BUT, the warmer the water, the less oxygen it holds...

It's because of all the stupid assumptions that I stopped posting threads in RIU

Have a nice day

A waterfall will cool the water by evaluation substantially below average ambient temperature. This does not happen with air stones because the compressed air is delivered hot.

Rather than assume no one else has anything useful to add, perhaps you could be a bit more open minded.

 

[Keesje]

Many here seem to assume that all ambient room temps are within reasonable tolerances. My room would easily stay in the mid 90*s if I didn't run the ac at ~ 85*s.

That means my rez water would too. Now you all may think very arm water would not affect the roots, BUT, the warmer the water, the less oxygen it holds...

It's because of all the stupid assumptions that I stopped posting threads in RIU

The differences of the amounts of oxygen in water at different temperatures are so small.
Water of 22 degrees Celsius (approx. 72 degrees Fahrenheit holds 8.83 gramm per liter.
Water of 30 degrees Celsius (approx. 86 degrees Fahrenheit holds 7.63 gramm per liter.
Just a small difference, so the plants will still get more then enough oxygen.
Maximum DO is very easy to reach.
So for oxygen reasons there is not much necessity to keep your water colder.
Diseases and temperature.... that is a whole other story.

Your polished ornamental stones btw have nothing to do with the temperature of your water or your roots.
The temperature would be the same if you would use any other medium.

 

[PetFlora]

The differences of the amounts of oxygen in water at different temperatures are so small.
Water of 22 degrees Celsius (approx. 72 degrees Fahrenheit holds 8.83 gramm per liter.
Water of 30 degrees Celsius (approx. 86 degrees Fahrenheit holds 7.63 gramm per liter.
Just a small difference, so the plants will still get more then enough oxygen.
Maximum DO is very easy to reach.
So for oxygen reasons there is not much necessity to keep your water colder.
Diseases and temperature.... that is a whole other story.

Your polished ornamental stones btw have nothing to do with the temperature of your water or your roots.
The temperature would be the same if you would use any other medium.

because the water is kept cool, the stones stay cool longer. this would not work the same with hydroton as they are too porous

your argument about oxygen at temps reminds me of those who argue against NitroFil in their tires

 

[PetFlora]

A waterfall will cool the water by evaluation substantially below average ambient temperature. This does not happen with air stones because the compressed air is delivered hot.

Rather than assume no one else has anything useful to add, perhaps you could be a bit more open minded.

It's not that I am not open minded, just not with stupid people. I have explained to you before that my house is plagued by mosquitos for at least 3 grows a year. They have gotten into open water and lay eggs, so as much as I like water falls, they don't work here

 

[Keesje]

because the water is kept cool, the stones stay cool longer. this would not work the same with hydroton as they are too porous

Of course not.
Once the medium has the temperature of the sourronding area, whether it be water or air, it stays that way.
No matter what material it is. poreous or solid.
Only when the temperature of the water or the air changes, the temperature of the stones will change as well.
If it would not stay the same, it would be in vialation with the law of Conversation of Energy.
Only it the rocks would be huge and you would put them in a refrigerator first and then put them in your reservoir, they will stay colder for a while.

your argument about oxygen at temps reminds me of those who argue against NitroFil in their tires

I don't know what you mean by that, as I have never heard of NitroFil.

But you for sure do not understand physics.
At least not that much when it comes to DO or temperature.

 

[PetFlora]

OK let's talk physics

you've seen pictures of the ornamental stones right?

Let's compare them PHYSICALLY to hydroton. Without using a thermometer do you honestly think that 72* water in the same volume of each stones will warm up at the same rate?

NitroFIl replaces the air in tires. They run cooler, have less moisture build up, and stay at pressure longer then ordinary air. However, the amount of extra Nitrogen is miniscule

 

[Keesje]

If your water is 72 degrees, the stones will have no influence on the temperature of the water. And vice versa.
Only if you keep your stones out of the system for a long time and heat them up or cool them down, it will have an influence.
And then perhaps your solid rocks will keep the heat a bit longer, or the cold.

Your NitroFIL has nothing to do with DO in water.
7.63 miligramms per liter in water of 86 degrees Fahrenheit compared to 8.83 miligramms at 72 degrees is so little.
That small difference is negligible.
It is not that if the plants use the 7.63 miligramms, that there is no oxygen left.
If you agitate your water it will ''fill up'' again.

Edit; IN POST 30 I SAID GRAMMS; IT MUST BE MILLIGRAMS OF COURSE.

 

[PetFlora]

You just can't let it go that you are wrong

This discussion is about cold, not heat, so stay focused

Unlike hydroton, which is very porous, the stones are essentially inert.

Start with a water temperature of say 72*s and maintain it long enough for the stones to absorb the cold, then let the temperature raise up. Do you honestly think in your wildest physics education that the stones won't keep the water cooler longer?

My point with NitroFii is that a small change in adding more nitrogen has a huge impact , so while you suggest that the small change in water storing oxygen at lower temps is insignificant,, based on what.. your impression/interpretation, your intimate knowledge of physics?

 

[Keesje]

Perhaps I don't get it, but that is mainly because you are not really good at explaining then.

Please explain better what you do with the water and the stones.
How long does the water stay around the stones for example.
If you talk about temperature, what temperature is raising. That of the air, of the water, or of the stones.?

 

[ttystikk]

It's not that I am not open minded, just not with stupid people. I have explained to you before that my house is plagued by mosquitos for at least 3 grows a year. They have gotten into open water and lay eggs, so as much as I like water falls, they don't work here

The very reason why well designed waterfalls are superior in my experience is due to the churning effect at the water's surface, which both oxygenates and kills anything that depends on standing water. It's also important to keep the lid closed so insects can't travel in or out of the tubsite.

I am not trying to argue; I really think proper design is critical to the performance I'm referring to. I've seen systems with mosquitoes and algae and I know what puts a stop to it.

 

[dstroy]

You just can't let it go that you are wrong

This discussion is about cold, not heat, so stay focused

Unlike hydroton, which is very porous, the stones are essentially inert.

Start with a water temperature of say 72*s and maintain it long enough for the stones to absorb the cold, then let the temperature raise up. Do you honestly think in your wildest physics education that the stones won't keep the water cooler longer?

My point with NitroFii is that a small change in adding more nitrogen has a huge impact , so while you suggest that the small change in water storing oxygen at lower temps is insignificant,, based on what.. your impression/interpretation, your intimate knowledge of physics?

He is telling you that you are explaining this the wrong way, which you are, it’s confusing but I think I understand why you are trying to say.

You are saying that the stones, because they have more MASS are more resistant to CHANGE when compared to other media.

And not that they have any effect on their own on the temperature of the water because that would be some flawed logic.

 

[ttystikk]

Water does cool by running over rocks for the and reason as swamp coolers work; evaporative cooling.

Waterfalls do it very well.