# Is mixing gravel with sand substrate a good idea?



## mik778866 (Aug 22, 2014)

I used to have sand substrate in my 2 foot (40 litre tank). When I upgraded to a 3 foot 80 - 90 litre tank, I changed to gravel substrate. This was because sand is too messy, clogs the filter & makes water changes a nightmare. I also did not have enough sand substrate and gravel also allows my to siphon which I feel is necessary. Plants seem to like sand though. I am thinking of mixing the two by putting sand below gravel. This irreversible move will give me the best of both. Is this a good idea, or a costly mistake? If I have to upgrade to a bigger tank will I be able to maintain the layers of substrate or Will it all get mixed up? See below for images


----------



## BruceF (Aug 5, 2011)

Is that first picture what you are calling sand? I find sand and gravel together doesn't work very well in the long term because the substrate just becomes too compacted and it is very difficult to replant things. However I am referring to s fairly fine grade of sand.


----------



## mik778866 (Aug 22, 2014)

Its not actually sand, but a messy substrate. Refer to link for more details of the substrate http://www.microbelift.com/products...aurium-products/biologically-alive-substrate/


----------



## HuntCast (Aug 25, 2013)

Your using commercial substrate with gravel it looks like. You can do it, but not sure a gravel "cap" will not end up mixed in the end. Prob better to just mix it, but might not look the best!


----------



## Diana (Jan 14, 2010)

As long as the materials are different sizes you will be able to separate them (it is a lot of work) if you decide you do not like it. 

The samples you are picturing are too close in size, you could not run that through a sieve and separate them. That is 2 colors of gravel. I would not suggest blending these 2 materials. You will never get them apart. 

Here is a suggestion:
Use a finer material as the planting material. Pool filter sand, EC, Flourite sands... 
Use a coarser gravel (whichever you like) cosmetically, as a cap. 
They will mix, somewhat, as long as they are in the same tank. 
When you want to upgrade you will be able to separate the materials with a sieve.


----------



## AshNeon93 (Jan 11, 2014)

I asked the same question a few weeks ago and someone said that the sand would lock in with the gravel causing problems, not sure how accurate this is but the people on here are usually right!


----------



## mik778866 (Aug 22, 2014)

I agree. Some experienced aquarist on this forum.


----------



## King of Hyrule (Apr 29, 2013)

I find the smaller grain (sand) settle below the larger grain (gravel). Overtime there is a clear delineation between the two sizes (of grains). People using eco-complete will attest to this. The shape of the grain also plays a role in how the substrate settles, more rounded shifts easier and separate faster.


----------



## Hoppy (Dec 24, 2005)

"Sand" and "gravel" have various meanings. It is better to discuss substrates referring to the approximate size of the particles. 2-3 mm particles work fine. Smaller than 1 mm particles, in my opinion, are too fine to use, whatever you call it. If you mix a large particle material with a small particle material the larger particles soon work their way to the surface, and the finer particles end up on the bottom. Eco Complete advertises this as a special quality of that substrate, but it isn't.


----------



## kman (Dec 11, 2013)

King of Hyrule said:


> I find the smaller grain (sand) settle below the larger grain (gravel). Overtime there is a clear delineation between the two sizes (of grains). People using eco-complete will attest to this. The shape of the grain also plays a role in how the substrate settles, more rounded shifts easier and separate faster.


This is true although the issue is compounded because Eco Complete is so lightweight.


----------



## mik778866 (Aug 22, 2014)

Thanks to you all


----------



## THE V (Nov 17, 2011)

I capped builders sand (2mm average size) with pea gravel in my low tech tank. Its been almost 4 years and the gravel keeps coming to the top. No compaction issues at all.


----------

