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I heard something about over-aeration. Is it true that fish get sick if you use alot of air in combination with powerheads?

I use a pipe with holes in it to spray into the water. This generates lots of bubbles that don't flow up to the surface but they stay in the water, gliding along on the stream of my powerhead. Is this harmfull for the fish? The bubbles are smaller than one millimeter. Some guy told me that they block the oxygenflow from the gills...

My brain says that this would be fine - but then I don't know for sure.

What can happen, however, is that the noise disturbs the fish too much...

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Mats

MatsP wrote:My brain says that this would be fine - but then I don't know for sure.
Mats

Over aeration is possible; one of my fish disease books had a pic of a fish with distress from air bubbles in its tissue from over aeration, I believe dissolved oxygen content. But I am with Mats in this case. Can't tell you why, but it seems ok to me. I am watching this thread for more info on this.

troi

That's correct Troi, it's called "gas-bubble disease" (he says in his most patronising voice)

It can occur when the O2 concentration in a liqiud becomes over-saturated. When the blood becomes over-saturated, bubbles will form as the blood is unable to hold anymore gas.

This I understand is what happens when you boil water. The first tiny bubbles that appear when the water begins to warm up are bubbles of O2 forming as the water is losing it's ability to hold dissolved O2.

This phenomenon causes gas filled blisters on the fish.

I think the risk of this is only in tanks that are either very heavily planted and/or with a massive algae problem, as the plants are able to produce huge amounts of oxygen under certain conditions.

I think there is no risk as far as powerheads and air pumps go, as these methods of aeration are limited by the atmospheric O2 concentration.

racoll wrote:This I understand is what happens when you boil water....I think there is no risk as far as powerheads and air pumps go, as these methods of aeration are limited by the atmospheric O2 concentration.

Blimey, man! You use boiling water in your aquaria? Perhaps I won't take any more advise from you ;-)

Hard to super saturate the water under normal temp and pressure situations this way. It stands to reason that the
bulk of O2 would just rise to the surface or circulate as bubbles. I do wonder about the original statement about actual air bubbles interfering with gill function, tho. Never heard that before and would love details.

troi

I've been reading some info on the internet (learned a great deal) and there was one site with some good arguments, arguments from some professors.

A short story on this subject:

"It said that pumping pressurized gasses into the water can oversaturate the water. But air that is mixed with water in a powerhead by means of the impeller is also slightly pressurized. But even then the gasses can escape at the sirface of the tank, so oversaturation will not be a common thing in normal fishkeeping.

When air gets into the water in a form of microbubbles that cloud your water it can be harmful to the fish because of the bubbles sticking to the gills of the fish. Causing it to interfere with the waterflow over the gills and irritating the fish.

However, these microbubbles can only do this when the water is full of them, you could see them floating around in your water actually making the water milky. A good test is to put yout hand into your water, not in front of where the bubbles are made, but in a quiet corner in the tank, if you see that bubbles are formed on your hand then they are most likely formed on the fish..."


I don't think that oversaturation is possible if your are not using pressurized gasses...

It makes me wonder if fish in a natural environment with splashing water full of this tiny bubbles is also harmed, I don't think so.

I lost the link to the complete story, but I will have a look and post the link...

Found the link:

http://www.oxyedge-chum.com/diffuser,_o ... ubbles.htm

This is just one link in the many links I found on google:

http://www.google.nl/search?q=microbubb ... art=0&sa=N

Some say it harms fish, some say it doesn't hurt them...

I think you're much more likely to disturb or even seriously harm the fish with water movement well before you have a trouble with too much DO.

Just put up an article on the subject in SW, might be that it could be added too...

Jools

Oversaturation isn't uncommon when filling new water to the tank - if you use tap-water, that is.

But that is because the water coming out of the tap is both under pressure, and cooler than the normal tank-water.

As stated in the quote above, it's unlikely that you'd oversaturate the tank unless you're pressurizing the surface, which would require strong seals and a good air-pump going into the tank.

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Mats

I agree, but what about the tiny bubbles that stick to the surface of the gills...

FrankieWilde wrote:I agree, but what about the tiny bubbles that stick to the surface of the gills...

From the links your provided, it looks like under certain circumstances they can be a problem in several ways. The real question, tho, is just how often will you create or encounter those circumstances in the home or LFS aquarium?

The concerns of these authors seem to revolve around "game fish" and short term conditions. I think the equipment is different from what we use. You would have to try pretty hard to create the dangerous levels micro bubbles in a hobbiest tank, IMHO.

The rule here seems to be "avoid excess" and remember, just because we can doesn't mean we should.

troi

I have a small 20gal tank with a 4" pl*co and a couple of 5" mirror carp. I was told that aration was a good way to help reduce ammonia concentrations and installed a "bubble wand" about a month ago. All three fish love it, they are more active and look much happier. Even the pl*co likes to play in the bubbles when he thinks no one is watching. Should I be concerned with the extra O2 harming the fish ? The tank has been established with the carp for about 2 years but the pl*co has been in for only about 2 1/2 months. I don't usually do any water testing but I change about 20% of the water weekly.

If you actually have ammonia in the tank, then you need to fix that... Any measurable amount of ammonia is a bad thing.

Back to your question, no any size bubble wand that actually fits in the tank would be just fine.

You are, I'm sure, aware that 5" mirror carp will not stay 5" forever, right?

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Mats

Should I be concerned with the extra O2 harming the fish ?

No, a regular air pump and airstone/wand will not cause any problems.

Yes Mats I'm awarwe that the carp will get much bigger, they have currently doubled in size every year so far. I know they can get to over 40 lbs and am planning a much larger tank. some people think I'm crazy for keeping them as they get pretty ugly when mature but they have imprinted on me and get very excited when I enter the room. They swim like mad against the glass like an excited pup when they see me. I can hand feed them.

I didn't suspect an amonia problem was just a little concerned about the overall water quality after adding the pleco , I know the carp are much more tolerent of poor water conditions than the pleco. I should proably start testing again.

know the carp are much more tolerent of poor water conditions than the pl*co.

Depends what sort of plec it is!


I presume it's a common ?


You could probably boil them in acid, and they would still be OK!

LOL. I'm not one for boiling fish in acid, but without going to ways of extremely abusing fish, the Common pleco's are pretty much bomb-proof. As long as there's some water in the tank [they used to export these fish wrapped in wet newspaper!], and it's not starved or overfed on meaty food, it'll live through anything. And if the carps don't outgrow their tank soon, the pleco probably will...

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Mats

Yes, it's a common Pleco, and I ihave no intention of boiling him in acid

I actually use a 40 gal. air pump in a 20 gal. tank because of my 1 white spot rubbernose pleco. It requires extra aeration. The only issue I've had with the pump is it tends to agitate the surface to the point where I get algae growth on the top of my glass plate! (The one in between the light and the aquarium)

I am no expert and cannot remember where I saw this but the article warned about over aeration and small bubbles but said it was only a problem in a salt water tank. The point was the little bubbles getting so thick they caused gill function problems. If you think about a protein skimmer you can see that this actually makes some sense. Salt water by its very nature seems to make a better froth.

Just my $.02.

George