Questions about sand and substrates

Back when I was setting up my planted 10 gal, I didn't really do much research regarding substrate and sand cap. I thought most sand is fine as long as they're nontoxic, and inert.

So I bought 7 kilograms/15 pounds of silica sand since it was labeled as "chemically inert" and topped off 1" of dirt in the tank.


here are some pics to get a scale of how fine the sand grains are


(here's one of the snails that loves to stir up and burrow into the sand, my guess is melanoides or some kind of trumpet snail, but I can't pin on what sp.)

And just now, I've read that fine sand can be bad for planted tanks as it gives oxygen a harder time to get underneath and reach the plant roots/make it too anaerobic for the roots?

Just also learned that silica sand releases lots of silicates in the water that causes diatom blooms. I guess it was already in the name, which is fair. I always thought that most sand substrates other than crushed lava rock, already have silicates on their own, so silica sand doesn't really affect anything in the grand scale?
(please take these with a grain of salt as I'm not sure of what I'm yapping about either, this whole revelation is recent for me and I'm trying to learn more about it.)

But I've been seeing brown diatoms pop up more often over the last few days, so I can't tell if it's just the "normal diatom bloom" new tanks experience, or it's the sand's silicates, or even the water I'm using? The shrimps and snails are taking care of them though.

back to the "Anaerobic substrate" problem, would burrowers and other fauna that stir up the sand help with that or make it worse? I've got some snails that love to burrow into the sand and poke out from time to time.


And lastly, what are your thoughts on this? Am I just being paranoid? I've seen people use fine sand for their loaches and plecos before, but what about the "bad" side effects to using them? This is all new to me and just discovered after one curious google search.
I guess it won't help me either way as I can't really do anything or replaced the sand in my tank now..

From the picture it looked like the sand was relatively grainy so it should be fine you can also get thing like under gravel filters though I don't know if you can get ones for sand. (I am a relatively new to the hobby so forgive me if I am wrong)

You should be alright, you've got a burrowing species of snail which act like earthworms in the aquarium. They keep the substrate aerated and healthy for planted tanks!

MorganJamesSimpson said:

From the picture it looked like the sand was relatively grainy so it should be fine you can also get thing like under gravel filters though I don't know if you can get ones for sand. (I am a relatively new to the hobby so forgive me if I am wrong)

Click to expand...

Sorry but you can't use under gravel filtration with sand. The problem is that the sand will sift down and settle under the filter plates greatly hindering the water flow under the filter plates. This is from one that has used under gravel since the 1980s and still does.