Originally Posted by ColoradoUtah
Now you have me confused after reading your comment about not vacuuming down into the substrate. Never?
I don't see how one can not go down into it at some point. It is gross! I leave the areas around the plants alone but where there are open areas I vacuum about once a month. I feel as though I have to because of the high bioload and nitrate history I have.
In some of my tanks, it is true that I never touch the substrate, not even on top. In a couple, I do. It depends upon the specific tank.
We forget--or don't initially understand--how important the substrate is in a planted tank. And this is not just because there are plants needing nutrients; it is because with
plants we can allow the natural biological system to work more on its own. But every time we start messing with it, by vacuuming the substrate or dumping chemicals, we are adding roadblocks.
There is a very significant and complex biological system operating in a healthy substrate. You might find my article on bacteria useful, rather than my repeating much of that here: Bacteria in the Freshwater Aquarium
My 115g 5-foot tank with a 3-inch sand substrate never has the substrate touched in any way. This tank gets a partial water change of half the tank every week, but I think I have only ever run the Python over a part of the sand once or twice, and that was for a specific reason. In my two tanks with loaches I do some substrate cleaning weekly, because the loaches burrow, and once of these tanks has had a couple of organics issues so I do a bit more than otherwise.
The type of fish can affect this; in a tank with messy fish like plecos one has to do more substrate cleaning. So everything has to be taken in balance.
Going back to the OP's tank, planted with one Betta, substrate vacuuming should never be necessary if the fish is not being overfed. Snails also help a lot, Malaysian Livebearing are ideal, also pond or bladder snails.