I posted this on The Planted Tank - Articles, Forums, Pictures, Links yesterday, so I apologize if anyone's is seeing this for the second time.

I'm getting a 30G tank that I'd like to conduct an experiment on for the substrate and could use some advice.

I plan on using native north texas soil, which is basically clay and probably not a whole lot of nutrients in it (I have no way to really test this to be sure that I know of) but I'd like to know if I can mix dry fertilizer compounds such as are sold from a hydroponics supply company.

My original thought was to add Iron Sulfate to the soil, which if I understand things correctly, is Iron in a ferrous state so should be accessible to plant roots, especially since I will be using a thin layer of peat moss to provide humic acid in order to help the plant roots access the iron.
Is this an accurate assessment?

Taking that one step further, are there other dry fertizilizer compounds that I should add to the substrate to provide a very nutrient rich soil for my plants? I'm guessing that things like Potassium and other macro nutrients are better absorbed through the leaves as part of my liquid fertilizer regimine, but what about other mineral elements?

Any advice is greatly appreciated. I'm enjoying taking this next step in the science behind a planted tank immensely.

Best Regards,
Kevin Stringer
kstringer1974@yahoo.com

I'd go to a lake or stream etc with some decent plant growth around it and fine a nice section of clay like soil, it ought to be fairly red and dense, there should be a black color further down, take some of each.

Next, you will use a screen and a bucket and wash the soil over the screen.
Decant after letting the soil settle for a day.

Allow to dry some to thick clay like paste.

Then use.

You can add KNO3, MgSO4 etc but all these are highly mobile nutrients and will leach out. It not likely you need any extra Fe if you use a clay rich soil.
KH2PO4 and Some CMS might help, a little peat as well.

Regards,
Tom Barr

Tom,

Thank you for the advice, I will definately try that out. However, does CMS stand for Concentrated Molasses Solubles? That's the only definition I could find that made sense in this context. If so, where can I buy this? I am not finding an online seller at first glance.

Thank you!

Here is a place to buy it: Rex's fertilizers for sale, but I don' t know what CMS stands for.