How Much Gravel Do I Need?

[Snowbrumby]

Hello,

When I got my tank I was told that I shouldn't use gravel as it makes it hard to keep the tank clean but that most people put it in because it looks nice. If I did want to use gravel to use no more than 1cm (1/4 inch) in depth so I could keep it clean. But since reading information on this site, the gravel seems to help by giving the good bacteria somewhere to live. So should I be increasing the depth of gravel in the tank and, if so, how deep should it be?
Thank you.

 

[pica_nuttalli]

i'd keep a nice thin layer unless you have live plants. the beneficial bacteria needs access to oxygen to survive and will pretty much just exist at the surface anyways. deeper gravel runs the risk of developing anaerobic pockets which, if disturbed, will release toxins into the water and possibly kill your fish.

gravel or sand on a tank floor looks so much nicer than just bare glass anyways.

 

[Snowbrumby]

Thanks for the reply I'll leave it as it is then. I like the look of gravel too, plain glass looks like it would be rather boring for the fish, they like to nose around in the gravel and see whats in there Though one day I'd like to change one of the tanks to sand as that looks lovely too.
I have learnt a lot more from the short time I have been coming to this site than from the lfs - and I tend to not believe the lfs staff much anymore - that's a good thing?? I come on here and check the info they told me first

 

[pica_nuttalli]

that's a good thing?? I come on here and check the info they told me first

that's not a good thing; that's an AWESOME thing! you rock, Snowbrumby. way to not be a sheep and get second/third/fourth opinions!

 

[charmd2]

snowbrumby, thou shalt never believe lfs employees without checking thier knowledge. One of the top rules of fish keeping.

(how often have they been wrong so far? out of curiosity)

A small layer of gravel is much easier to keep clean than a thick layer. The debris settles through gravel and accumulates under it.. Nasty, Much easier to vacuum a thin layer.

I have sand in all my tanks. Well.. Almost all my tanks, my beginner ten gal still has gravel, but only because it is now my snail breeding tank, and I don't really mind the leftover food and stuff in it. It gets cleaned every two or three weeks compared to the larger tanks that get twice weekly cleanings. (only snails live there, and they are a food source for my oscar)

So basically If you think it is good, You appear to be researching options well, then you're probally ok.

 

[FrAnK3333]

1 pound per gollan is the guideline I use.

 

[The-Raven]

1 pound per gollan is the guideline I use.

....Good lord.

I have a 29 gallon tank and I used 8 pounds (which gave me about an inch of gravel spread around evenly)

29 pounds would just be... wow...

 

[pica_nuttalli]

you should only do pound per gallon if you're planting. even then its a bit deep. i personally try to make do with as shallow a layer as i can get plants to root, which works out to about an inch deep on average. my tank is only 1/4" where i've got pots and blank space. where i've got plants is probably 1.5" deep. all my driftwood sunk on its own, so i've just got the bare glass underneath it and gravel pushed up to the sides.

 

[NinjaSmurf]

That's almost like a trick question if you put in a pound for each gallon, because each pound you add takes away from the total gallons, and if you keep adding gravel, it keeps eating away at the actual gallons of water....


I have too much time on my hands...

 

[nc_nutcase]

So a four foot 110 US Gal aquarium should use 110 lbs of gravel to cover it's 6 square feet of floor space?... I thought we wanted somewhere between 1/4 and 1 inch? That would be more like a foot of gravel!

 

[Jezah]

One pound per gallon is way off. Maybe not for saltwater tanks, but for FW...ya...too much. I would say about a inch is good. Any more and those nasty anaerobic pockets start popping up.

 

[The-Raven]

So a four foot 110 US Gal aquarium should use 110 lbs of gravel to cover it's 6 square feet of floor space?... I thought we wanted somewhere between 1/4 and 1 inch? That would be more like a foot of gravel!

what are the dimensions of the floor?

I would guess that somewhere around 20 pounds is a good bet for a 110, that'd get you around half an inch, depending on the dimensions

 

[The-Raven]

One pound per gallon is way off. Maybe not for saltwater tanks, but for FW...ya...too much. I would say about a inch is good. Any more and those nasty anaerobic pockets start popping up.

if you have an undergravel filtration system, would this tend to cut down on those anaerobic pockets?

 

[Jezah]

Ya, maybe. Still, the middle layer, the one the undergravel doesnt touch and the one the regular filter doesnt touch...would still develop pockets. It just has to do with no air reaching certain spots, creating spots for bad toxin to develop.

 

[pica_nuttalli]

One pound per gallon is way off. Maybe not for saltwater tanks, but for FW...ya...too much. I would say about a inch is good. Any more and those nasty anaerobic pockets start popping up.

if you have an undergravel filtration system, would this tend to cut down on those anaerobic pockets?

ugf actually work best with a very thin layer of gravel. you would acheive the maximum amount of biological filtration possible via just gravel if you had a layer exactly one unit of gravel thick because every unit of surface area would be in an aerobic condition. as the layer of gravel over the ugf increases, the amount of water circulating between particles decreases and the likelihood of anaerobic pockets increases. thus you want to have as thin a layer over your ugf as you can stand.

since plants and burrowing critters interfere with ugf function, you wouldn't *need* a thick substrate layer anyways (these being the primary reasons to have a deep substrate.)