I would really like to put sand in the aquarium (I was thinking of covering 1/2 - 2/3 the tank surface with sand), but the owner of the tank is afraid that it will be too much work to maintain when I'm no longer around to look after it.

Based on some readings about other bottom dweller fish, I got this idea that it could be possible to have fish that regularly 'stir' up the sand (by burrowing?) for you so that you only need to vac the top once in a while. So, would this be possible and what type of fish would I need to keep the sand loose and clean?

If I do go with sand, how would it work to put the sand on top of a layer of gravel? The gravel is pretty average in size but a little coarse. I'm thinking I might like to plant some of the sand, but would like to provide something solid for the plants to root in. Our filter creates quite a stir/current.

Thanks in advance!

You'll find that the sand will over time sink to the bottom and your gravel will be on top. Best to get rid of the gravel. I think that some loaches (e.g.Khuli?) do a fair bit of burrowing.

I think its wishful thinking to think that there will be a fish that will do this whole maintenance job for you. I'm not a sand expert at all but I've read any number of threads indicating that you should use a long probe or other object to loosen the gravel to its full depth in order to stop any anaerobic pockets before they progress too much. While there may be one or two species that burrow like crazy, I wouldn't think these would be the types found in typical community tanks, particularly ones with non-floating live plants.

People who have direct experience with sand should be able to advise better.

I've never understood how people could get along for very long with 2 or more separated types of substrates. The first time you need to pull them out of the tank its going to be near impossible not to have a lot of mixing. I guess you could use sieves, but how tedious! Or you could buy new substrates periodically I guess...

~~waterdrop~~

I guess some people use gravel tidies to separate the layers? TBO I've got no idea what I'm going to do as I've got a 1-2" sand fertiliser mix on the bottom and then two different sized and separated gravels on the top. I guess I'll just do my best to separate the larger gravel as that cost the most but I don't think I'll need to worry about that for a couple of years yet.

Sand maintenance? I put sand in my FW tanks about 2 or 3 years ago and have never gone near the sand since.

I can't help but feel some people make this hobby harder than it really is...

My corydoras do a great job of cleaning up food and turning it

Have to admit that I do sometimes give my sand a bit of a stir with the gravel vac post-water change. But maintenance seems rather a grand term for this 2 second procedure.

I think I read a thread (probably an old one) where you and some other guys were debunking the idea that anaerobic pockets (or the gas that bubbles up from them or something!) were dangerous to fish. Do you remember anything about this and could perhaps explain it to us? (I don't understand the history of why anyone would have been worried about it in the first place. I've experienced, years ago, blackened gravel associated with poorly maintained undergravel filters and such..)

It comes up fairly often. Bignose has pointed out that the harmful substance which can be formed by anaerobic bacteria (hydrogen sulfide) becomes harmless the moment it comes into contact with oxygen. We know our water has oxygen in it as the fish are alive. It was discussed in a thread in the scientific forum.

One of the things that made me feel it wasn't so bad before Bignose posted information like the above is the fact that marine fishkeepers actually desire anaerobic conditions and bacteria to help deal with nitrates. I couldn't believe that something that was so great in SW would be so deadly in FW. You can still end up with blackened areas of sand or bubbles up against the glass, which some people don't like, but then you are into aesthetics. I find a perfectly clean substrate far from top of my lists, which is why I stopped doing any sort of gravel vac some time ago, preferring instead to just pump water out and fill from the cold tap, thus allowing me to change large volumes of water quite quickly.

kooli loaches and corys stir up the sand pretty well, but i don't touch mine and its been in my tank for 2 years i run my finger along the bottom glass to get rid to the black but thatrs about it

Thanks Andy, that's -exactly- the discussion I was trying to "dredge up" (so to speak, lol).

So as far as recommendations to beginners, I was concerned that perhaps most of the experienced people have the correct or over-filtration needed to handle any ammonia spikes that might occur from buildup of excess waste in the gravel, whereas some of the beginners we advise here might very well be under-filtered and could easily suffer spikes if they have excess build-up. What are your thoughts on that? What might our best approach be for gravel-cleaning recommendations for newcomers who ask?

(I personally don't have enough quality experience to ascertain the best recommendation for beginners.)

~~waterdrop~~

Simply "pun-derful"



Gravel is slightly different. With gravel you can have physical waste get trapped lower down and break down without being pulled out. Whether this will cause an ammonia spike I don't know. With sand, it is very easy to see the physical waste as it sits on top (leading to some people feeling that sand looks dirtier quicker than gravel and never looks as clean). As the waste sits on top of the sand, I don't really think that the depth is going to have any real effect on ammonia levels.

In marine keeping there is a belief that Deep Sand Beds can become nutrient sinks, and if disturbed they can release the nutrients they have stored back into the tank/system (which is why some advocate remote sand beds which are 50% changes every 6 months). In FW terms the effects are minimal, the boundaries between success and failure are slimmer with SPS corals than with FW fish.

I would just advise people normally: do regular water changes and if you can see waste on the bottom, have a go at vaccing it up at water change time. I would expect that to do them fine.

However, as some may have noticed, I tend not to follow the advice given out by many of the members on here