[Robert Hudson]

adding MTS to keep it turned over.

I think their benefit is overstated. They help, they are harmless, but they burrow only deep enough to barely cover themselves, and in compacted sand, I do not think they would do much if anything to help.

My experience with sand... compact, compact, compact... Within only a few months it got so hard I could not poke my finger through it. Plant growth slowed down, I had dead spots all over the substrate where the compacted sand cut off oxygen and tuned the sand black from rotting organics. It smelled like rotting eggs, and some of my fish started getting sick.. lathargic, stopped eating. It was a huge mess.

That was several years ago. Since then I have tried growing plants in sand with no fish, because sand was cheap. My Cryptocorynes will simply not grow in it. Plants that responded well from water column ferts and plenty of light seemed to do OK.

 

[Robert Hudson]

Well everybodys experience is a little different I guess. I used it in 20 and 30 gallon tanks and still had the problem, but I know you are not alone in your experience. I can understand the use of sand for its asthetic value, but it has very little other benefit. It contains no minerals that plants can use, is usually alkaline, and has no CEC capability, (the ability to hold metal ions, nutrients from the water).

Now, I am setting up soon a paludarium of sorts for fiddler crabs where I plan to use sand, rock and mondo grass, and maybe a couple other bog plants such as Acorus. The plants will grow above water with their feet in the sand and water. I think they will do OK.