Res aeration... how much?

So... 200 litre (45 gal) low profile res.... how much aeration is required?

I have a 4 outlet aquarium air pump and i plugged 2 lines and ran air stones on the other 2 in the res. The amount of bubbling seems insufficient. I thought of unplugging the other 2 lines and adding stones, but i guessing that the pump just doesnt put out enough pressure to make much difference.

But maybe im wrong? I just dont know how much aeration is required?????

What are other folks doing for same size res?

Correct me if I'm wrong but you're going to be growing flood/drain style if I remember correctly. You don't need to aerate your reservoir with flood/drain actually. With that said, I don't like things to settle, just feels wrong so I added an extra water pump with a venturi fitting that I run for 5 min at a time a couple of times a day. I personally hate the sound of air pumps and stones don't create much surface tension anyway unless you get a very a large (louder) air pump.

Major Blazer said:

Correct me if I'm wrong but you're going to be growing flood/drain style if I remember correctly. You don't need to aerate your reservoir with flood/drain actually. With that said, I don't like things to settle, just feels wrong so I added an extra water pump with a venturi fitting that I run for 5 min at a time a couple of times a day. I personally hate the sound of air pumps and stones don't create much surface tension anyway unless you get a very a large (louder) air pump.

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Yes... flood and drain.

No need to aerate the under table res? What sort of witchery is this? Lol

It goes against everything i have learned. But then i havent grown hydro before. Just in peat....

In my mixing res barrel, i put pump in to make a water fall... keep things circulating and aerating... as i was told this was the easiest way. Not sure how often to run it though. Cant be 24/7 because that would prolly warm the water too much? I dunno.

Anyway, so how does the under table res get aerated if no stones or waterfall pump?

My flood and drain res is under my table and every time the system drains it creates a waterfall affect going back into the res. I've been running flood and drain this way for 9 years now.

I'm sure adding air stones would be great but you shouldn't NEED them.

Thundercat said:

My flood and drain res is under my table and every time the system drains it creates a waterfall affect going back into the res. I've been running flood and drain this way for 9 years now.

I'm sure adding air stones would be great but you shouldn't NEED them.

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Hmmmm.... thats enough aeration? Even if you flood 2 or 3 times per day? Ill be using rockwool slabs. (I was told by hydro store guy that 2 or 3 floods a day in veg would be about good... and then maybe 5 or 6 times a day in flower.

But, my drain hose goes all the way down under the remaining water in the res. I have a lid on the res and cut holes in it to run the lines up and down. Any leakage should drain through the holes, i figure.

No need to aerate a flood and drain reservoir. When the flood table drains the water draining out pulls in fresh air to the roots. As long as you let the have adequate time between floods you will not have any issues.

Well I don't use a drain hose, my drain just free falls about 12-14 inches from my table to the waterline. With the pump I have it takes about 10 minutes to fill my tray and then it stays running another 5 minutes because my timer has 15min intervals. While it is still running it starts draining and airating. I just cut a square out of my res lid to allow enough space for the drain to pour back in without splashing all over.

I personally don't like rock wool. It holds tons I water from my experiAnce. However I've never grown a crop on it I have only cloned with it. When I tried it a couple times for clones I didn't like how long they stayed wet.

I've pretty much always done my flood and drain with grow rocks or hydroton which ever was available.

The effect renfro talked about is the key. It's why its important to allow the medium to dry a little in any growing medium. As water leaves the medium it pulls air in to the roots.

I haven't don't it yet but I've been toying with the idea of putting an air stone at the bottom of each of my pots of stones. Ideally I'd like to design a pot with an air manifold built into the bottom. The idea being to pump some air straight into the roots. It would also dry the medium faster which would allow more watering a per day.

Gquebed said:

Hmmmm.... thats enough aeration? Even if you flood 2 or 3 times per day? Ill be using rockwool slabs. (I was told by hydro store guy that 2 or 3 floods a day in veg would be about good... and then maybe 5 or 6 times a day in flower.

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I would flood once every couple of days in veg and max 2x /day in flower with rockwool cubes in a pot. I can’t imagine needing more than that considering how much water those slabs can hold. Bad advice

I just hate washing rocks... so i was trying to get away from them. Lol
But im not committed yet to any method. I am a little skeptical about rockwool because of my cloning experience with them... just thought with a bigger roots system they wouldnt be such a problem.

Renfro said:

No need to aerate a flood and drain reservoir. When the flood table drains the water draining out pulls in fresh air to the roots. As long as you let the have adequate time between floods you will not have any issues.

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This makes a lot of sense.

Major Blazer said:

I would flood once every couple of days in veg and max 2x /day in flower with rockwool cubes in a pot. I can’t imagine needing more than that considering how much water those slabs can hold. Bad advice

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The rockwool slabs i was thinking about come in long bars that are wrapped in plastic. Ill take a pic when i hit the grow shop later...

I got 2 big stones in my 20gal rez on a drain to waste system.

More the better

Gquebed said:

I just hate washing rocks... so i was trying to get away from them. Lol
But im not committed yet to any method. I am a little skeptical about rockwool because of my cloning experience with them... just thought with a bigger roots system they wouldnt be such a problem.

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I hate washing rocks too. I've got an idea for an automated rock washers but haven't build the prototype yet.

I hate the idea of buying and throwing out rock wool more though.

Gquebed said:

The rockwool slabs i was thinking about come in long bars that are wrapped in plastic. Ill take a pic when i hit the grow shop later...

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I knew what you meant, I just poorly worded my reply. I meant to convey that my watering cycle when I used Rockwool cubes was such. Those slabs hold tons of water, I doubt your mileage will vary much if at all. That hydro store guy is tripping with 5-6x a day floods in RW.

I used to run 4x8 trays in a CO2 enriched balls to the walls environment. I had to flood for 20 minutes to reach full depth on a 4 hour delay. My SoG ended up about 40-44 inches tall when flowering freshly rooted clones. a little over 2 pounds per 4x4. Just buds on a stick, no small stuff as that is all butchered off at 20 days into flower.

Rockwool does hold too much h2o in my opinion and it's also a powdery mildew attractant. Expanded clay pellets for the win.

Renfro said:

I used to run 4x8 trays in a CO2 enriched balls to the walls environment. I had to flood for 20 minutes to reach full depth on a 4 hour delay. My SoG ended up about 40-44 inches tall when flowering freshly rooted clones. a little over 2 pounds per 4x4. Just buds on a stick, no small stuff as that is all butchered off at 20 days into flower.

Rockwool does hold too much h2o in my opinion and it's also a powdery mildew attractant. Expanded clay pellets for the win.

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How many clones in the 4x8?
Also, do you find the clay pellets (hydroton?) Leave sediment in the res?
Dont they float?

Rinse the rocks first and strain out the tiny rocks to trash. No problems after that.

Shouldn't be many floaters, a couple here and there, just toss them.

96 clones in a 4 x 8 (7x7 grid minus a couple for where the fittings come up.) Trellis at about 30 to 32 inches up from the pots. I used 6 x 6 inch square pots. Clones were cut about 6" tall and rooted for 20 days so they were very well rooted and trying to veg.

Major Blazer said:

I knew what you meant, I just poorly worded my reply. I meant to convey that my watering cycle when I used Rockwool cubes was such. Those slabs hold tons of water, I doubt your mileage will vary much if at all. That hydro store guy is tripping with 5-6x a day floods in RW.

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This is what i was talking about. Sounds like you know already though. But even in the vid the guy says flood and drain keeps the slabs too wet. So i dunno... the guy at the grow store was talkin shit i guess...

Lots of grow store guys talk all kinds of shit to sell stuff. They want to sell the highest profit margin items usually.

The times I've seen those slabs used successfully were always dtw drip systems.

Renfro said:

Rinse the rocks first and strain out the tiny rocks to trash. No problems after that.

Shouldn't be many floaters, a couple here and there, just toss them.

96 clones in a 4 x 8 (7x7 grid minus a couple for where the fittings come up.) Trellis at about 30 to 32 inches up from the pots. I used 6 x 6 inch square pots. Clones were cut about 6" tall and rooted for 20 days so they were very well rooted and trying to veg.

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Its that rock rinsing i hated when i was doing soilless. But i spose itd be a lot less rocks than i had to use before.