im tearing down my tank, and i figure ill try something different. currently i have 40lbs Tahitian Moon black sand. i want to find a good substrate to mix with my sand that will retain the dark black color but also provide a benefit to my tank's Flora and not harm my tank's Fauna. nor do i want to annoy my roommates with anything that will smell terrible over time (as from my research some potting will continue to decompose and produce foul odor). i suppose i would want around 15lbs of this "desired substrate"

1st hand experiences would be much appreciated ^_^

If you are only going to need one bag or so and are using it for a planted tank I would highly suggest Flourite. They make a black blend and also a black sand mix now which would go well with your current setup but provide additional support for any plants.

You can also opt for the soil which works as well. If you do choose potting soil ensure it has no fertilizer additives. If you go this direction just make sure to wash the soil thoroughly outside of the tank. A few good soaks in a container should do the trick. This does two things. First is moistens the soil and allows it to not cloud the tank when you do add water in the tank itself (this process is good for the Flourite as well since it has a nasty habit of clouding the tank for a day or so)

2nd it will help to wash away any excess material was left in the soil. After the soakings just stick it in the tank and put your gravel bag over it. Pretty simple and the soil is much cheaper($2-5) then the Flourite ($20) both will work.

he said it all lol.

If you dont want to change substrate plants will do fine in sand because their roots can easly grow in it. Then just get a liquid fertilizer i use " florinmulti" or "floringro". I have a 55 gal planted tank with some low-medium plants and thats what ive been doing and they have been growing great! My tank is a jungle.

Strike.. I'm betting you were waiting to see how long it would take for me to weigh in on this one~!...<grin>.. Flourite/smourtie/crapite... I've yet to see something that contradicts the suggestions of Diane Walstad's theory/practice. A $1.00 dollar bag of potting soil, covered by about 6 bucks of pool filter sand, proper number of fish and plants and from then on.. just trim back the foliage!.. No ferts, no CO2, very few water changes.. Just trying to recreate nature at its best.. AND in your fishroom!..

I think that the bio load will have a lot to do with the balance in that system. One too many fish and things get out of whack. I know it works as you can see in many systems in nature but one thing I think of is that even in a natural environment things don't always work. You see pond and lake systems that clog up or have fish die off. Many of it is caused by a natural occurrence but still.

The main difference between the potting soil vs a clay (flourite) substrate is the ability of the substrate to hold nutrients and to have the nutrients it contains be replenished. I would say that most soil has a lower CEC then a clay. It is because of this that through long term use the soil has the potential to run out of it's nutrient carrying capacity and at that point stops helping the plants. The clay has a better exchange rate with the water allowing it to pull and hold nutrients and therefore exchange them over a longer period of time.

This is just from what I have learned by reading what others have found. I highly doubt that there would any noticeable difference in the short term test. It may take several years to see a change.
Who knows!?

Strike.. I can't begin to argue with your perspective.. you've put a ton more research than I have.. but.. (I always have a but)... The key to your post is one word..."balance".. That is the core of my belief. Pick a fish you want to raise.. find the plants you want to compliment that fish)es).. and maintain a balance between those elements.. In my case, SA's, clay is as foreign a material as is kryptonite!.. I believe that you can establish a natural tank environment with the same basic elements that nature provides in the environment your trying to re-create... Water, plants, soil and fish.. Juggle those 4 balls and it tends to balance things out.. oops.. that word "balance" once again... Depending upon the "purchased" substrate rather than the natural development of the natural environment leads you to endless maintenance. LOL.. Take care my friend.. Bill

I agree bill it is all about balance the only real problem with that is if you try to completely re-create a natural environment you would end up with a 500gallon tank and 4 fish... What I am getting at is that the vast majority of natural environments don't even come close to what we have going on in tanks. Even a light to moderate stocking has more fish per gallon then almost any natural environment.

SO what really ends up happening in a balance system is you have to tip the scales. You recreate an unnatural environment (concentration of fish, plants, volume of water, filtering, light,) and try to hit a balance with what you have. In the end it is a beefed up version of nature but most certainly not natural even if all the processes involved are.

Way way way off...LOL.... In some SA environments there are like a thousand inches of fish per gallon.. and yet they're there because they've found the right environment... I've one tank set up.. only 35 g.. with like 30 tets.. two big angels, 3 cory's and a single pleco.. that I would drink out of.. and while it's only been up for 2 months next week.. (the day after I signed on to the box) the water/ammonia/nitrites/nitrates can't be beat... without any w/c's, ferts, co2 and ONE vaccum effort. And I am now at the stage of having to harvest some of the plants I got from you last month!... My next tank has only been up for just over a month and set up before I embraced the Walstad mindset.. and it's close to gin clear but not there yet.. again.. only fish/water/soil.. no ferts, co2 or any tweaking of any kind. The 3rd tank, I was a bit anxious to set up the 55g and went without the soil.. Now on two weeks, bi-daily w/c's of 10% and it's just starting to be something to look at and be proud of... It is soon to be torn down and re-established with the soil/sand setup.. It works for me.. and I'm sure your proceedures work for you.. I just don't have to work so hard at it!... LOL... (for anyone following this thread.. Strike.. is one hellova aquarist).. I'd listen to him way before I'd take my advice.!... Bill

Well I didn't say all systems where like that but you have to account for water volume and exchange in those systems that would out pace any of our meager attempts at filtration. There is simple no way to completely re-create nature.
We do out best at it and the simple approach you take works great! Keep in mind even though the system works to start nature is a long term machine. Like I was saying in terms of bio-load if the waste produced out paces the waste reduction by just a little it will over time lead to the downfall of the system if left untouched. There is no real way to know when that will be or even if it is happening until it is likely too late.
I have also noted in other threads that many people seem to think that ferts, co2 ect are needed to grow plants and this is simple not true. Turn on the lights and your plants and fish will do the rest... BUT if you want to grow plants at a much faster rate (unnaturally fast) the ferts, CO2 and all the other crazy things, even substrate comes into play. This is not to say the simple system does not work because well... it clearly does! BUT like so many people of there the ability to see fast results drives towards the extremely train of thought and overtime it becomes the norm. I admit to being a person who pushes to see what they can do and have managed to accomplish exactly what I was after.

And you Sir, are what I have found to be the "go to guy" to deliver results via your processes... Me?.. I just wanna go find another tank to buy and start!..LOL... I tip my hat to you .. Bill
but.. I've been organic for close to 20 years and try to carry that history over into my newly invigorated interest into the hobby hence my naturalist approach.. Plus I'm as tight as a drum with a nickel ..

Haha bill I always keep in mind that there are more then one way to do anything. I attempt to provide prospective in a generalized sense. Never to say that one things or the other won't work because every time I do it does! What I like to know is WHY it works and can it be reproduced. To be honest much of my life is like a giant experiment and the search for more information is the driving factor behind it all!

LOL.. back in the day.. in a long ago land.. believe it or not.. I used to "experiment" with mind altering drugs.. At times I think I'm still having flashbacks but at least it left me open to different perspectives...