Aeration Diffusion stones and pumps

[Aleman]

Those are very big bubbles . . . ideally you need smaller bubbles, as that gives you a greater Surface area to volume ratio, and more gaseous exchange. When my wort is flowing into the FV with the O2 on it looks milky because of the bubbles . . . . . sort of like Guiness just after the pour

 

[Vossy1]

Aleman, do you think the larger bubbles are due to the high flow rate, whatever it is ?

Ps, the bubbles coming out of the stone are quite small but they join up rapidly.

 

[Wez]

Wouldn't a high flow rate cause smaller bubbles, the forced out effect?

 

[Vossy1]

:hmm:

 

[Aleman]

I don't really know what causes it . . . . I do know that when I use my 0.2 Micron stone 'static' (dangles in the wort) I get much bigger bubbles and it takes longer to 'saturate' the wort.

You will need a high flow rate . . . I suspect that when you have wort flowing over the stone the bubbles will be much smaller.

 

[Wez]

In all honesty I was just thinking about how much the loo water foams up when i've been desperate to pee :shock: :grin:

(wez - disclaimer - not really - I was trying to be a clever git)

 

[Vossy1]

My replacement Morebeer aeration stone came today with 2 extra filters discs included.
Unfortunately someone at Morebeer thought the fiters would survive in a very poorly lined jiffy bag for the journey over the pond ...I don't feel like complaining again

 

[Vossy1]

Would you believe Morebeer are sending me 2 more filters out :party:
I've gotta say that Morebeer customer service is absolutely fantastic, one of the best I've ever had, based on this and other order experiences

 

[Vossy1]

Well, the new filters arrived and I used the airstone for the first timeon my last brew...but...a question for all you experienced airstone users.

Is it normal for the stone to block?

It started with great gusto when the pump was first turned on but this reduced to a trickle with 15 minutes use.
My first thoughts were the pump isn't up to he job. I took the airstone off and replaced it with a spare and got the same high initial flow rate.

I tried to blow through the suspected blocked airstone and it was definately blocked :hmm:
I had cleaned the airline prior to use and dried it thoroughly. I'm at a loss at the moment.

 

[Rabmaxwell]

Hello all i am planning a brew & want to use my stainless airstone with mini compressor set-up.I have 2 taps fitted to my Fv so will pump wort from one tap to the other tap with airstone in the middle.The thing is i want to plug it into my timmer so it will switch on & off.How many hours into the fermentation should i stop aerating the wort. Cheers

 

[Rabmaxwell]

Hello Vossi looking back at your post your aquarium pump looks identical to mine.I had the same problems as you it worked at first then got blocked that's why i bought the mini compressor.Have you managed to get it to work yet. Cheers

 

[MEB]

Well, the new filters arrived and I used the airstone for the first timeon my last brew...but...a question for all you experienced airstone users.

Is it normal for the stone to block?

It started with great gusto when the pump was first turned on but this reduced to a trickle with 15 minutes use.
My first thoughts were the pump isn't up to he job. I took the airstone off and replaced it with a spare and got the same high initial flow rate.

I tried to blow through the suspected blocked airstone and it was definately blocked :hmm:
I had cleaned the airline prior to use and dried it thoroughly. I'm at a loss at the moment.

After reading the reply from RM i will say that the aquarium pump is not suitable. I worked as an aquarist(not in retail shops but for public aquariums) for 8 years(6 years before that in aquarium retail shops) and we never, NEVER used stuff thas was sold as 'aquarium' stuff. It's made to a price not to a spec. Most aquarium air pumps are not designed to cope with a build up of back pressure as that isn't supposed to happen. They are designed to flow air with very little back pressure and certainly not through airstones of the like you are using. We used great big compressors. Far more efficient, easier to filter the intake of air and capable of blowing airstones into shrapnel. Which was often the case. The issue you have with aquarium air pumps is that they don't build up a pressure of air they just pump it. So when a back pressure builds up they fail to deliver. Which is what's happening with yours V1 i reckon. You want something that pressurises a small cylinder before delivering the air. Thus the pressure in the cylinder is blowing the air not the actual compressor action. A small airbrush compressor should work fine and it'll last for a long, long time. I don't think you'll find a cheap way of delivering compressed air. I went from aquarist to diver. Lots of compressed air used in both activities. I tried loads of stupid ideas before i took the plunge and bought a real compressor for aquariums. Now i have a bloody fine compressor that can pump up dive cylinders to 310 Bar. Thats a real compressor. Probably a bit OTT for what you want though. But an old dive cylinder filled to 200 bar will deliver all the air you'd want for years i reckon.

 

[Vossy1]

Hello Vossi looking back at your post your aquarium pump looks identical to mine.I had the same problems as you it worked at first then got blocked that's why i bought the mini compressor.Have you managed to get it to work yet. Cheers

Ermm...yes and no Rab. It works fine in water, but in the fv it slowly blocks up :wha:
I know a few people who have the Morebeer set up including the pump as supplied by Morebeer and they've had no problems with it. The pump I've got is piston driven as opposed to the diaphragm pump as supllied by Morebeer, so it far more capable.

When the airstone flow has stopped it is BLOCKED, though I don't know how it's happening.

But an old dive cylinder filled to 200 bar will deliver all the air you'd want for years i reckon

Good call MEB. I have a C02 cylinder, I'll attach that and see what happens. I'll slowly up the pressure until the stones working properly, but won't go to high, as the air lines I'm using aren't that strong

 

[Vossy1]

I just tried the airstone using my C02 cylinder as the gas source and it worked no problems at all, even with the C02 reg reading next to 0 PSI

I should have listened about the mini air compressors...looks like I'm going to have to buy one...when finances allow

 

[MEB]

I just tried the airstone using my C02 cylinder as the gas source and it worked no problems at all, even with the C02 reg reading next to 0 PSI

I should have listened about the mini air compressors...looks like I'm going to have to buy one...when finances allow

Aquarium air pumps are rubbish mate. The daft quotes of X litre's per min are absolute rubbish. I've seen aquarium pumps that reckon they deliver 400 LPM. :shock: Which is about twice as much as a small dive compressor?????

You'll love those little mini air compressors, bit noisy but great little bits of kit.

 

[Vossy1]

Would you belive the little pump did it's job today :twisted:
Still going to get me one of those compressor thingies

The antifoam didn't do it's job today ...or maybe it did, as I have nothing to compare it to :lol:

 

[Aleman]

The antifoam didn't do it's job today ...or maybe it did, as I have nothing to compare it to :lol:

Well one way to test is to transfer/aerate the wort with no antifoam . . . then once you have filled the FV with foam . . . squirt in a couple of ml of AF mixed with a bit (5-10ml) of sterile warm water . . . . The foam should immediately disperse to a a much more sensible level. . . . This is my normal practice with O2 as it allows me to fill the FV with O2