The Puffer Forum

Sorry, I helped hijack lil fish's thread on the hospital so thought I'd start one here.

Are 'micro bubbles' harmful?

Or is this just a myth?

I'm talking about small skimmer bubbles, which are not really micro at all

I did have issues with this when keeping seahorses, but is this the only case?

I could understand how there might be problems if you had saturated gas in solution, then either increased the temperature or salinity suddenly. Neither of which should really happen in 'real life'. Suspect what's goin on inside a fish is not quite the same as outside in the tank as well but am really not sure.

I'm really asking - 'Can fish get 'the bends'?' or is that a myth too?!

Micro bubbles from a HOB skimmer or return pump are not really harmful, (no idea about horses because they are not a typical reef tank creature) Micro bubbles can get trapped under plating SPS and cause dead spots, this can also happen if you have a really bad micro bubble problem so much so that bubbles get trapped in the live rock creating dead patches.

Really micro bubbles are bad because they make the water look not clear.

Q: "can fish get the bends?"

A: I would think no because they are not breathing the nitrogen rich air that happens with deep scuba diving.

One of the biggest problems with micro-air bubbles, to the point that water looks milky, is the fact that they stick to everything, scales, slimecoat, gills, eyes, gut, etc. This can actually inhibit oxygen transfer across the gills, cause an air emboli with pressure changes and cause build up in the swim bladder and gut. Short term exposure to this is ok and is considered a good thing in protein skimmers because it creates more surface. I really don't care for HOB skimmers because of they don't try to achieve the micro bubbles as small as in sump. In the sump Skimmers should be in their own compartment with a bubble trap before the return pump (my opinion, take it for what it's worth).

As for fish getting the bends, yes they can. The bends is caused by dissolved nitrogen in the water and when that dissolved nitrogen is exposed to less pressure it comes out of solution causing air bubbles in tissue. With air being composed of a high concentration of nitrogen, the air bubbles can cause the bends if the fish is transported rapidly from differing atmospheres of pressure.

Edit:As for HOB skimmers I should have said older ones. The newer HOB skimmers do have air traps, how good they work I don't have any experience with so I can't speak to that.

What about aging water to get rid of nitrogen bubbles? Important or not?

Not really. Aging water is not really going to get rid of too much dissolved gas.

I dont think dissolved nitrogen gas is a worry at all with typical reed/marine fish keeping...

And you have to have one hell of a carbonated tank for the fish to have issues with bubbles LOL

Excellent replies, thanks