Changing Substrate - Gravel to Sand

[GouldyUK]

Hello there!

My tank's been established for about 6 months now and is coming along very nicely. When I originally purchased it (from a mate at work who was moving and no longer had room for it) and set it up I kind of bought the substrate, pea gravel, without putting too much thought into it.

Now I've done a lot more research i'm regretting the fact I didn't put sand in instead.

Does anyone know if changing the gravel for sand is possible and if so, how you would go about it?

Any comments warmly received!

[Richard B]

It is certainly possible - have you a pic of the tank? or can you describe it - ie furnishings , planted?

[MatsP]

At least two plausible ways:
1. Use a large diameter hose (at least 3-4x the grain size of your gravel), and siphon out water and gravel in one go. This works very well, and is very low "mess factor", as you are sucking up any "mess" in the gravel along with the gravel. Obvioysly, you will have to remove any plants, decorations

2. Remove a fair amount of water into a temporary container (rubbish bin, bucket(s) or similar), and put the fish in a "temporary" home (e.g. a bucket), and drain the as much water as possible, then use a scoop to remove the gravel.

A third possibility is to layer sand on top of the gravel, and then wait for the sand to sink down through natural movement, and over time, remove the stones that come up through.

--
Mats

[RickE]

Adding the sand to an established tank isn't too hard either. I've recently done this and the only things I would say are:

1. Get it reasonably clean. Although the filters will take the muck out, there's no point in chucking a load of dirt in there.
2. Get it up to room temperature at least. It's surprising how cold damp sand can be if left outdoors at this time of year.

I just used an old pyrex bowl as a scoop and put it as close to the bottom of the tank as I could before tipping the sand out. It didn't make much mess at all.

[wrasse]

A third possibility is to layer sand on top of the gravel, and then wait for the sand to sink down through natural movement, and over time, remove the stones that come up through.

Its a bit late for April 1st, isn't it?!?

[MatsP]

I was not joking.

--
Mats

[Shane]

1. Use a large diameter hose (at least 3-4x the grain size of your gravel), and siphon out water and gravel in one go. This works very well, and is very low "mess factor", as you are sucking up any "mess" in the gravel along with the gravel. Obvioysly, you will have to remove any plants, decorations

This is my mainstay technique for replacing substrates. I have a 1.5" diameter 4' clear piece of tubing I keep on hand for just this purpose (and for doing REALLY fast water changes sometimes). You can often get all the gravel out while only removing as little as 1/3 of the tank's water.

Before you dump in the new sand substrate be very sure to turn off all filters. Even very small particles of sand can really wear out a magnetic impeller on a filter over time. In fact, on any tank with a sand substrate I would recommend a sponge prefilter to protect the inner workings of the power filter. Let the sand settle for an hour or so before turning the filters back on.

Lastly, because I just recently really messed this up, remember the substrate in the bucket when you go to empty it! I have a tank with a substrate of gravel I collected in Lake Victoria, Uganda and packed all the way back to the States. The other weekend I siphoned out about 1/3 of the gravel (it was too deep) and forgot it was in the bucket. I then chucked the bucket out in the backyard and watched my Lake Victoria gravel all fly out across my lawn! No way to get that back.
-Shane

[GouldyUK]

Brilliant fellas, thats all really helpful.

And the million dollar question, what sand should I be looking at? Do any of you have personal preference in terms of how yours is set up?

[Richard B]

Senegal sand from Unipac is my favourite, but there are lots of suitable sands - find some you like the look of and then ask your questions here.

[sidguppy]

Mats is smack on the money here, folks

if you want to leave the fish in peace and even leave the plants in place, the best way to go at this is to simply add clean sand in small bits

the sand will slowly "trickle" through the gravel; but fish like Corydoras or other diggers help a lot

eventually the sand will be on the bottom, the gravel on top
if you siphon the gravel bit by bit, it'll take a few weeks; but you end up with a sandy substrate and you never had to disturb the fish or even the plants

works like a charm
;)

[MatsP]

I use sand from the DIY stores - there are several kinds that work - Playsand should be fine, but I use mainly "Kiln Dried Paving Sand" - that's the stuff you use for block paving and such to fill in the gaps between blocks - it's usually quite clean in the bag, costs about £4 (about US$ 6) per 25kg (~50lbs).

--
Mats

[dw1305]

Hi all,

A third possibility is to layer sand on top of the gravel, and then wait for the sand to sink down through natural movement, and over time, remove the stones that come up through.

&

Mats is smack on the money here, folks

if you want to leave the fish in peace and even leave the plants in place, the best way to go at this is to simply add clean sand in small bits

the sand will slowly "trickle" through the gravel; but fish like Corydoras or other diggers help a lot

eventually the sand will be on the bottom, the gravel on top
if you siphon the gravel bit by bit, it'll take a few weeks; but you end up with a sandy substrate and you never had to disturb the fish or even the plants

I've done this as well, and it works really well.

cheers Darrel

[MatsP]

Having said that about adding sand on top of gravel: If the sand and gravel are close in size, such as in my RIO400 tank, where I added "half the tank" of sand, and put fine gravel (2-3mm) in the other half, the result is, after a few years, that the sand and gravel is pretty well mixed. So there needs to be a decent difference in size.

--
Mats

[dw1305]

Hi all,
The other thing I should have said is that if you have a tank with high flow, this will sort the substrate into coarser in areas of high flow, and finer in areas with less flow. I actually use this sorting effect with fine sand/coarse sand. I originally got the idea from one of Haarvard Stoere's posts.

details here:
"Sand or Gravel"<http://www.planetcatfish.com/forum/view ... 3&p=225167>

cheers Darrel