Seedlings and light with drip system

[bufo marinus]

There you go Pot Head

Nice pic Gazza.

Hey Indy did your Hydroton grow have no other air supply other than the same as this one?

And it worked ok?

Did you finish a harvest with no pythium problems?

Using Oxy plus or similar ?

[Indycar]

Yeah, i had that joiner to suck air into the line while waterin'. But found it a pain in the arse. While it's taking air into the line, it spurts nute solution everywhere for a drip system due to pockets of air going off once exiting sprinkler head. So i ditched, and replaced it with a airator (which runs 24/7) and air stone (a bar 30cm long). I found it wasn't necessary to run the pump 24/7 as the roots were dangling in the nutes. Nice bubbly solution constantly churning over. The only reason i bothered with the 15min every 2 hours was just to wet the upper roots down.

 

[bufo marinus]

Yeah, here is the slight difference with potheads system; his needs the pump running 24/7 to aerate the solution and root zone whereas Indy's runs a sererate air pump 24/7 to keep the oxygen levels up which also keeps the solution and root zone healthy, but also allows the pump to shut off and fresh oxygen to be drawn into the root zone.

Perlite works exactly the same as the Hydroton; it is that correct mix of watering and aeration

Coco is similar but doesn't seem to suit drying out like these two above

[Indycar]

Yeah, the way i see it. While you have a pump running 24/7 your generating friction, which in turn is slowly raising the temperature of the water (moreso in a small system like pothead's). Fair enuf, airating the method i was using does generate heat, but i doubt it would to the amount of a submersible pump running 24/7.

 

Plus, it's acts as a backup system having a airator. If the pump fails, it's not as critical as having a system relying on pump alone. As the plants root system is still recieving both nutes and oxygen, until you have sufficient time to source a new pump.

 

Each to their own though. By adding a proper airation system to it, it's taking potheads system to the next level i tend to believe. For an additional $20, it doesn't seem a too shabby of an idea.

 

It was a concept i borrowed off the northern hemisphere lads with their bubbler buckets. But there's no exact science to hydroponics,from what i've learnt so far. What works for one person, may not work with another...

 

[moKing]

I'd get that airstone in soon as you can, the plants will love it. That's something interesting what indicar was saying about prepetual motion pumps heating things with friction. Heat isn't an issue to myself but if this is a problem mabey you could look into air lift pumps. I've heard of these beeing used in aquaculture but I'm not sure if they would work, i think they might require a bit of depth. If anyone has tried these i wouldnt mind knowing how they went.

 

peace

 

moKing

[bufo marinus]

Hey Indy I have used exactly the same rationale in trying to cut down on heat in the past, as no matter how you look at it that pump does create heat.

Does it create more heat than can be lost by the res? Maybe, I'm sure it wouldn't help though.

Of course adding an extra air stone would be a good, cheap idea regardless imo.

Speaking air stones and aeration, from what I have read it is the bursting bubbles that actually oxygenate the water so the more finer bubbles the better. Another thing I have also read is that a tumbling effect like a mini waterfall is the best way to oxygenate water.

I gave my plants a dose of pythium that bad once I now run twin airstones plus a 500litre an hour pump with the fountain attachment plus use HySan to aerate the solution and keep things sterile. Overkill? Yes. But do I have worry about aeration or unhealthy res any more? No.

[Indycar]

Yeah, plenty of ways to skin a cat...

 

I would prefer a overflow effect, but it was unknown to me at the time. But for $20 that got me outta the shit, i can't complain with what i had. But i had to do something at the time as the method the pump mentioned was causing more greif than what it was worth. Between water going everywhere and possibly burning the plants while they were wet under a hot light was'nt a good scenario. Let alone possibly blowing a bulb...

 

[Gazza2001au]

u fellas sure u aint using water heaters? haha ive used a few size/brands of water pumps and air pumps but none have heated up at all of corse in theroy a the cheap/small air pumps pass the air across the motor before entering the pump diaphram than into the hose but this hasnt been enough to heat up my nutrients?

[bufo marinus]

Yes for sure mate, there are heaps of ways to go.

The tumbling effect I rabbit on about is from a second pump and happens in the res, I have a lovely little fountain happening in the res hehe

Once again I'll quote something from the Flairform web site. This is a great guide on aeration and also clarifies oxygenation and water temps with a bit of science using Henry's Law

 

 

Aeration of nutrient

Plants require oxygen in order to respire. For this process, plants uptake oxygen via the roots, not the leaves. It is important to note that the oxygen must be dissolved in water (nutrient solution) in order to be up-taken by roots – it cannot enter a root in gaseous form. Note, oxygen also aids in keeping the nutrient sterile due to its mild disinfecting properties.

 

To support optimum plant growth, a nutrient solution generally requires a minimum oxygen concentration of around 3mg/L. It is generally noted that super-oxygenation fails to deliver improved growth result. Also, there is a common belief that high temperatures cause oxygen levels to become inadequate. However by referring to the chart below you can see that water can hold 7mg/L oxygen when at 40oC. Growth problems at higher temperatures could be attributed to photorespiration, increased bacteriological activity, etc.

 

As with stagnant water, simply exposing a body of water to air does not aerate it. System design generally determines how much oxygen becomes dissolved in the nutrient.

 

Maximum aeration is achieved by breaking the water up into as small a particle size as possible via a tumbling (e.g. waterfall etc.) treatment. In hydroponic systems, aeration can be achieved by delivering the nutrient to the plant / channels via spray jets. A second opportunity (for recirculating systems only) is to design the hardware such that the nutrient splashes into the reservoir (tank) when it returns from the roots. In either case, it is critical to ensure that the air is well ventilated where the aeration occurs otherwise that air will quickly become stale (i.e. depleted of oxygen).

Direct air injection into the nutrient using an air stone and air pump can be used to compensate for poor system design / poor aeration. This is the method commonly used in fish aquariums. However, be sure to use an air-stone which produces the smallest bubbles - this will maximize its effectiveness. Also, locate the air stone’s pump in a well ventilated area.

 

Unrestricted root growth - Because new roots are the main supply route for oxygen if new root growth is restricted then oxygen supplies will be restricted.

 

Oxygen solubility in water using Henry’s Law

 

Temperature (oC)......Temperature (oF)......Oxygen concentration (mg/L)

 

0....................................32................................15

 

10..................................50................................11

 

20..................................68.................................9

 

30..................................86.................................8

 

40.................................104................................7

Edited January 19, 2007 by bufo marinus

[bufo marinus]

Well pumps do produce heat Gazz. I thought it made sense to take it into consideration.

As I say above, does the pump produce more heat than what that body of water can evaporate? I doubt it but it can't be helping eh?