Loaches Online Forum

Right,
two things of late: a) added a marbled headstander who promptly ate all my plants and b) added 10 med & large mystery snails. Did a deep-sand gravel/sand vacuum yesterday and very little "crud" came up. Far (far, far) less then usual, at least. In part there was little/no plant bits, but there was just very little generally as well.
Is this normal? Is it the lack of plants or is it the voracious appetites of the snails eating, well, everything including fish-pooh? I also notice there's little hairy algae on the gravel (cleaner then ever in past >4 years) and the bamboo is starting to break down. I see the headstander eating both and assume the snails are doing same.... only faster. glass is also cleanest it's been in years.
A

Sounds normal to me. I do not have any, but I have heard that the headstander may nibble on plant leaves, soft shoots, and green algae.

If the mystery snails are helping then I should get some...I have heard that some snails carry diseases, and parasites? If they do, how can you be sure that it is safe to add them to your tank

Sounds like between them, the fish and snails are cleaning up a lot of stuff. As far as ecosystem goes, this could be a good thing, but is only temporary.
Without live plants or algae in the system the nitrogen will start rising. All the elements the plants were removing will now start building up.

In a system with plant eating fish I would try several things:
1) Feed lots of vegetables in hopes the fish will not eat the plants.
2) Add plants that they like more (to be eaten) and plants that fish generally do not like (Hoping they will not get eaten)
3) Use a 2-tank system, such as a tank with a sump/refugium. Grow plants in the refugium, and pump the water through so the tank benefits from the live plants, but the plants are safe from the fish.

Plants that fish tend not to eat:
Java Fern, Anubias, Bolbitis.
Plants they tend to really like: Elodea or Anacharis, the highest priced plant in the tank.