Sorry, somehow I missed your comments there. How do you think compost would work? I have a pretty good amount going. Was going to use it for the gardens next year but I can always sneak some into the tank. Never even thought of it....
The trick pony (my thinking) is finding something that releases low amounts over time limiting what ends up in the water column. Tree barks and chopped wood fines take more time for the bacteria to break down as opposed to tuber plant debris and grass cuttings. Time released plant foods for the growth in the tank. A rich compost mix might release to quickly (I don't know).
On the other side of this opinion is what Dogfish has done within his tanks.
Forum search posted threads by Dogfish and you will find amazing extremes proving points many thought would lead to disaster. (including me)
I've settled into using M
(potting mix) contains soil and a large portion of organic material (55-65% by volume). Sphagnum peat moss, composted bark fines, leaves, twigs, wood chips etc. and "pasteurized poultry litter" (cooked chicken crap).
MGOCPS although a number of folks have used it both intended and by mistake. It contains cow manure and all using it report ammonia spikes the first few weeks using it. Manure tends to spike ammonia early on in a rather rich release. So I stay away from manure rich mixes.
or mix up something similar to the following;
50% composted tree barks and fines, 30% sphagnum peat moss and 20% worm casting. Powdered clay can also be added to the mix if you like.
About a 1.5 to 2" layer of the mix capped with 1 to 1.5" of fine gravel or coarse sand.
Using either one moving rooted plants you have to work slowly moving things around and pulling plants.
tip; setting up the tank hold back a baggie full of capping material or even several lbs. if you like for the long term this can be tanked. Touch ups are needed time to time. Much later I find it hard to find a good color match as even flourite batches vary. (imo) Bang for the buck and the least effort go dirt because it works
More people seem to be deciding on dirt tanks rather than waiting for the soil to be mineralized or going with daily dosing EI, high light and CO2 lately. Asking for options, I think this is cool
. Hopefully most are reading enough information first and thinking it through. Several years ago most were high light tanks that were the topic here on TPT. Most still are but we the dirty are growing in number LOL
Two HUGE considerations doing this.
Using 'natural' soils READ the contents on your bag of dirt if you bought it. I know it contains dirt,,, (duh),,,
but NO COW crap in the bag plz! Small amounts of chicken waste can work but no! no! moo! moo!
. Worm castings are another option. Still other mixes but that's for others to post about as I post what I use.
Also remember PLZ that while natural tanks (dirt base) and seeded filters can be stocked from day one go lightly with your first stocking list. Dirt goes through changes going from dry to saturated (submerged) and the rate of break down on the organics changes too. Sometimes it can be more than the tank and fish can handle.
For the first couple of months whether you want to or not test your water weekly. Starting out every couple of days for ammonia and be ready to change it if the soil burps (it can happen). You might have a tank like most of mine that ran straight through the issues quickly and were trouble free from then on. The majority of new setups here never tested for cycling shifts on the water tests. Lots of plants (including floaters), no hard scape to trap the soil gases, control the light (a big key to dodging algae), watch things and let the tank settle (month maybe two). The capping material needs to be small enough to contain the soil yet allow the gas exchange to occur.
That's the first trade off for not waiting for the dirt to finish the mineralization process outside the tank. Attention starting out, more or less high maintenance in the beginning., Things can get busy if a bump in water parameters occurs. All the organic material and the bacteria that chew through it do give you free CO2 for a period of time.
The second major trade off you make with any soil base is that rooted plants should be there to stay. Placement is important. Removing plants with a good root structure is a HUGE PITA. I had an Amazon Sword that had to go. Cutting around the root ball directly under it I killed the plant taking it out and left all the root runners in place. Thinning a field of crypts means a water change and repairing the cap adding more material. Soil tanks are a set it and forget it type of tanking (imo). If you like to change things around, re-scape, swap out plants then soil use is not for you. If you want to top off the tank when the water gets low, trim to make room for the fish to swim and not dose for months it might be what your looking for.
Any number of things can vary on how to care for a system once established but large rock placement, big plants, things of this nature need to be thought out ahead of time. Pushing growth with higher light energy, CO2 injection, water column dosing all can be added,,, or not.