Sand?

[Joeyg2100]

I am going to be putting 4" of sand in the bottom of my 30 gallon tank for my Arrowhead puffer to burrow in, and I was wondering how often I have to swril the sand around to keep the "toxic gases from building up? Thanks

 

[BigIan]

http/www.fishforums.net/index.php?showtopic=131373&hl=

have a read of that my boy

 

[Captain Retardo]

4 inches is too much, i have read that a half or a full inch is good, otherwise anaerobic pockets will quickly build up. Burrowing fish like yours will break them, but i think 4 is still too much.


Edit- 1-2 inches is fine, but i guess as the posts say below me, if you stirred it enough, you could get away with it

 

[plecoguy]

i have heard other sides of the story to. i talked to a chemist who was explaining how yes, in a deep sand bed anaerobic bacteria will build up if not stirred, but when released it combines with the oxygen in the water to become not toxic. I havent really met anyone who has had troubles before, and infact in saltwater a deep sand bed is desired because the anaerobic bacteria eats nitrAtes. i dont think you will have a problem, and 4 inches will be nice for your fish!

 

[BigIan]

or as the other thread says just make sure you have plenty of critters in your tank to eat anything before it gets into the sand...

 

[smithrc]

Mlasyan trumpet snails will be a great addition.... the puffer can eat them too

 

[Iron Man]

As the years have gone by many saltwater aquarists have found that their deep sand bed only stored up what it "ate" and released it later.

If you're willing to stir the sand bed with your hand every few months and the tank isn't overrun with bioload....you won't have a problem.

I had a deep sand bed in my cichlid tank (4 inches silica sand) because I just liked how it looked. I stirred it with my hand every few months and never had a problem.

Just remember that there are pockets under rockwork, etc that can develop. Make sure you get everything.

 

[Synirr]

Captain Retardo -- .... Yeah, that's why Joeyg2100 was asking about stirring it!
You can have any depth substrate as long as you stir it occasionally. I stir mine about once a month or so and haven't had any problems. In my 80 gallon it's about 5", nice and deep for my midas hybrid and oscar to dig in . The midas keeps most areas pretty well stirred up by constantly digging and moving things around.

 

[annka5]

..or buy a heating cable, which pulls cooler water down thorugh the sand as the hoter water rises, so supplying the bacteria in the sand with oxygen.

 

[Joeyg2100]

..or buy a heating cable, which pulls cooler water down thorugh the sand as the hoter water rises, so supplying the bacteria in the sand with oxygen.

I heard of this. Where can you get these at, and what do they look like? I don't know if I will do this as Arrowheads burrow themselfs, so I don't want to have the fish burn himself of the cable.

 

[annka5]

I got mine from a garden centre that does a good range of aquatics; its made by JBL and cost £25. I'd be inclined to have a look on e-bay or whatever first. They're long relatively thin silicone covered element that is completely flexible - kind of look like string made out of silicone, with a plug, and suction cups to attach to the bottom of the tank glass. By the time you put the sand on top the suction cups and cable are completely invisible.
I actually don't think they get warm enough to burn a fish, though am not sure how you could test this to be sure! They're not designed to heat the tank, only the substrate, so you'd still need a heater.
They're also meant to be great for plant growth as most aquatic plants prefer their roots to be warm.

 

[Bignose]

I posted this about a month or so ago, it talks about how almost anything created under anaerobic conditions is rendered harmless as soon as it comes into contact with oxygenated water: http/www.fishforums.net/index.php?showtopic=123698&hl=

The main concern people have about sand would be anaerobic bacteria build-up. Anaerobic meaning without air, though more accurately, without oxygen. If you didn't know, the ammonia and nitrite reducing bacteria require oxygen to work (to convert ammonia to nitrite and to convert nitrite to nitrate).

Anywho, under anaerobic conditions, bacteria start to get their energy from other sources, like reducing sulfur instead of oxygen. And a by-product of that is hydrogen sulfide, yes, one of the deadliest compounds in nature.

But, there is relief. In water, as soon as hydrogen sulfide comes into contact with any oxygen, it will become harmless. So, even if there is a pocket, and even if you accidentally stir it up, it will become harmless as soon as it hits your well-oxygenated water. And you know your water is well-oxygenated since your fish are living in it, and they need oxygen.

So, there really isn't anything down there to worry about, so my recommendation is to not stir it at all. Just vacuum the top of the sand to get the uneaten food off the top. If uneaten food on the top is a constant problem, you probably should be feeding less, maybe a lot less.

p.s. Another source of energy anaerobic bacteria may use is actually to convert nitrates to nitrogen gas. This is what living rock and living sand does for some marine tank setups. There is no way that I am aware of that "pockets of ammonia" could form the substrate. If there is oxygen present, ammonia will be converted to nitrate, if there isn't oxygen present is will be reduced to nitrogen gas. As far as I know, ammonia would be consumed by the different bacteria species in either case.