I'm not an avocate of soil in planted tanks, it causes algae in the initial set up stages and it's an unholy mess.
I've used Onyx sand and leonardite and peat and a bunch of detritus/mulm from an established plant tank/filters/gravel etc. I used peat and gravel in the past for many years, long before there was a "web".
Non CO2 tanks can be taken to much higher level than many believe.
After a few months, the nutrients are depleted in the substrate. All of your nutrients will come from the water column from that point on unless you re enrich the substrate.
The traces and Ca /HCO3(KH) from onyx is ideal and helps speed the cycling of fish waste up vs plain gravel.
The part about no water changes............yes, it works, I know why it does, she mentioned why as a wild card guess, she says it's allelopathy, I've argued a very very strong argument against that hypothesis.
For example, what are the odds that all 300 species of aquatic plants have the same effect and produce allelopathic chemicals that provide plant growth and no algae? Close to the same odds that I might win the lottery.
Allelopathy has never been shown to occur in the field ever.
These are a couple of things that make this arguement virtually indefensible.
This argument was suggested for both CO2 and non CO2 tanks. I see no evidence of it. If you add activated carbn to the tank, this will remove any allelopathic chemicals if you want to try it as a control(CO2 ore non CO2) or do large frequent water changes(CO2 enriched tanks only).
When you do a water change, you add new tap water in, this has very high CO2 most often.
Plants and algae both adapt well to either a CO2 rich environment(high CO2) or a non CO2 enriched system(Low CO2).
The water changes throws the plants off and many species of algae are able to bloom and get a quick start. The extera CO2 also causes the plant to use up most of the nutrients to the point where they can no longer use them, but the algae are much better at growing at very low levels of nutrients than the plants.
If you vary the CO2 levels with your gas system, you can get some nasty algae outbreaks easily.
Many have observed this. If you do this weekly or often, this becomes an issue.
Plant very dense from day one also. Add algae eaters, yes, don't do a water change! Sounds weird, take my word for it.
CO2 and non CO2 systems seem very different but they really are not that radically different.
Growth rates are different, that's the main thing. They are easier to care for, they can also grow almost every plant you can ion a CO2 enriched tank with a few additions.
I add SeaChem Equilibrium each week and some KNO3/KH2PO4/Traces, not very much, just a tiny bit.
I can grow almost any plant, just slower.
I've dosed high levels of KNO3/KH2PO4 also, but if you want to not do many water changes, do not do this, your plants do not need much in a non CO2 tank, just a little.
Folks should try non CO2 tanks, most are very happy, they allow for laziness.
Regards,
Tom Barr
