How do I clean sand without disturbing it?

[sylvia]

Simple question - how do you know nothing can get down there? The anaerobic bacteria won't necessarily feed off fish food - other dead micro-organisms and stuff that was already in the tank or sand can feed them as well but don't you think some water does get down there? You never know what sort of tiny particles of fish food are in it... As for it being a myth - have you never seen a bubble rise to the surface when you move even ordinary gravel around? I have so I am sure it's possible for such pockets of gas to form in sand - only they'd have no way of escape. Obviously the gas that builds up in gravel is probably just carbon dioxide from the aerobic bacteria but in sand it could be a lot mroe dangerous. As for 'never having problems' - you won't until the pressure builds up too high or something stirrs up the sand and releases it. Even then, the gas may not kill the fish but to be on the safe side I'd stick to assuming it isn't a 'myth'. Also, planted tanks have a lower risk of this happening (or at least a lower risk of it being dangerous) as the plants will use up the dangerous substances whilst also preventing anaerobic pockets from forming or coming to the surface.

 

[heresmike]

... - have you never seen a bubble rise to the surface when you move even ordinary gravel around?

After many many years in the aquarium hobby, no, I have never seen a bubble rise to the surface when moving gravel around. I've never seen it when moving the sand around either. This is what I base my "myth" theory on.

 

[sylvia]

Do you use large gravel or something because I am certain you MUST have bubbles of some description. The bacteria that break down ammonia/nitrItes release gases so unless you have lots of gravel-shifting species I can't explain your never having seen this. Oh well. Maybe you just didn't notice. The point is that it isn't a myth. There has never before, to the best of my knowledge, been any speculation over this and it is the first time I have seen it suggested to be a myth. There is a possibility everyone's been wrong about this but I rather doubt it. I am certain, however, that to be on the safe side we should assume it is true until someone can provide scientific evidence that it is not.

 

[freddyk]

1) 'pockets of gas' is not a myth, but it's very rare. Typically you will only see it in unplanted tanks that use too much sand, and yes, I have known one person to experience the problem.

2) By providing good water flow at the bottom of the tank I never need to touch my sand. Plant roots and snails turn it, the water flow makes sure it doesn't settle, so debris quickly gets sucked up by the filters.

 

[Griz]

Exactly what type of "gas" are we talking about? I am not aware of any gas that could build up in such concentrations that it would adversely affect the health of a fish.

 

[Morrgan]

Anaerobic bacteria can appear when the bottom substrate doesn't get any oxygen. By mixing the substrate around now and then you make sure oxygen reaches all of the substrate. In a tank with plants, digging fish or for example malaysian trumpet snails, it might not be necessary to do anything yourself, just let them handle it.

The anaerobic bacteria are basically "rotting" things. The result can be one of several foul-smelling compounds, such as methane or sulfuric acid. Some of them are toxic to fish.

 

[nerfhearder69]

Personally I only have a gravel substrate, fairly fine at that and I regularly get gas bubbling up. It's definately methane and I've checked all my books and the net and never heard of it being harmful. I assumed everyone experienced this and that it was a signifier of normal bacterial activity? don't tell me I've got something else to worry about.

 

[Morrgan]

I assumed everyone experienced this and that it was a signifier of normal bacterial activity?

Sorry, but methane is not normal. It's a sign that your gravel is "clogged". I'm not sure about the following, but one would think that it could be that if you get methane, there's a risk that other, more dangerous substances that are produced under the same conditions could build up in the future.

Do you vacuum the gravel regularly or is it too fine? Vacuuming it should keep this problem away. You could also stir the gravel a bit when you do the regular maintenance (water change etc).

 

[nerfhearder69]

I vacume once a week but just the surface I don't stir it up while doing so though. by the way I originally filled my filled my tank about three inches deep with gravel,would this have any connection?

 

[Discomafia]

3 inches is quite a bit, after all, even planted tanks only need 2 inches... So why do you have 3?

 

[Morrgan]

I originally filled my filled my tank about three inches deep with gravel,would this have any connection?

The deeper the gravel is, the more difficult it is to keep the lowest parts of it with enough oxygen. So yes, I do believe there is a connection.

 

[dothedew]

http/www.fishforums.net/index.php?showtopic=68838&hl=

Don't post the same topic in multiple forums. Ugh.