are airstones necessary for marine tanks?

[wave_dive]

I've got a tropical tank with an air stone and was curious about marine tanks - are they similar in this regard?

It's probably a silly question, but I just thought I'd ask.

So, to confirm, do I need to add an airstone to my new marine tank or is it not necessary?

Thanks, Laura.

[zenfox8]

You don't actually need an air stone in a freshwater tank, to be honest. The bubbles are in the water for such a short time that they don't really contribute to gas exchange. There's a bit of surface agitation, but it's minimal compared to directing the outlet of a powerhead or filter at the surface.

In a marine tank, an air stone can cause a lot of salt creep and blow bubbles everywhere. I wouldn't recommend using one in a marine tank, except maybe in a sponge filter for a fry rearing tank or in a skimmer. As for freshwater, I only use air stones to power filtration, like UGF or sponge filters.

[knightfox]

Andy's right. I thought it worth mentioning that air bubbles can cause problems for some inverts like sponges.

[zenoxa]

I'd say that's not entirely accurate, as natural reefs are in a constant state of turmoil, which actually results in a significant amount of bubble activity.

[rusticore]

It really depends on what kind of marine environment you're trying to replicate, Lynden - is it deep water, shallow water, a tide pool, or open ocean?

Just to clarify, sponges aren't coflakes, by the way.

The thing is, some organisms might be sensitive to air bubbles, while others probably won't be bothered. I'm guessing filter feeders, like sponges, brine shrimp, or even clams, might not appreciate air bubbles getting in the way of their feeding.

[zenoxa]

When sponges are removed from the water, they can get air bubbles trapped inside, which can cause them to decay from the inside out. However, I'd like to clarify that having bubbles circulating around them underwater won't have the same effect.

In my view, my initial comment still holds some merit, considering that a large proportion of the animals we keep in our tanks originate from reef or tide pool environments.

[rusticore]

I understand where you're coming from, but deep water reefs do exist, and we do draw from that pool of life. I still believe my point about reefs held water, and I wasn't referring to the open ocean in general.

[zenoxa]

Many species do originate from deeper areas, like sponges, anthias, and basslets - those aren't typically reef or tide pool dwellers.

[rusticore]

I'm thinking of stocking my marine tank with some live rock, a few mobile inverts, and possibly some non-photosynthetic corals, although some of the ones we keep do live in caves, which doesn't necessarily mean they're deepwater species.

[wave_dive]

Thanks so much for the feedback, everyone - really appreciate it.

I was actually told by a local fish store that bubbles were a must for my freshwater tank, which is pretty funny now that I think about it.

Glad to know they're not as crucial as I thought, to be honest I sometimes forget to turn them back on after feeding anyway.

I think I'll just leave my marine tank as is, no bubbles needed - thanks again for the advice.