Talking to another hobbyist this was the response i got and he is the Go to guy about planted tanks in my local fish club.
I don't mean to come off as being offensive or condescending and I have no idea where your local club is located but part of the problem
may be you are talking to the "local
fish club plant guy". There are a lot of local clubs with very knowledgeable plant guys in them and there are some "local experts" who think having a couple Java Ferns and Anubias in their fish tank makes it a "Planted Tank". Whether or not your "plant guy" is an "expert" comes down to what his (and your) definition of a planted tank is
There is nothing wrong with being "old school"...some still like to use heating cables, still like to put nails in the substrate for a source of iron, still believe you don't need CO2 to grow plants well (you don't if you pick the right plants) and still use shop lights with T-12 bulbs. Their methods work for them and the plants they choose to grow but may not work for me and the plants I want to grow. It really boils down to what type of plants
you want to grow and what
your local water quality is like. Here in Dayton, I can't grow many of the softer water species like Toninas and Eriocaulons very well because our water is so hard. Aqua Soil would probably help me grow those types of plants since it does lower the KH and GH (at least I think it lowers the GH) of the source water. However, I will probably be able to achieve very similar results by mixing RO water with my tap water, which is what I am in the process of doing right now.
In all reality, you can grow plants in just about anything...gravel, sand, dirt, etc if you learn how to use fertilizers. I prefer to use 3M's Color Quartz sand over the commercially available substrates like Eco Complete or Aqua Soil. The sand does not add any ammonia/ammonium to the water column nor does it increase or decrease the KH or GH of my source water. Using an inert substrate, like 3M's Color Quartz sand, lets me control my water parameters without any influence from the substrate. That way, the only one I have to blame for bad plant growth or algae problems is me
I've used Eco Complete, Fluorite, Flora Base, Schultz Aquatic Plant Soil (SAPS), Soilmaster Select (SMS), plain gravel and plain sand and have not noticed a great deal of difference in plant growth between any of them. I have gotten substantially larger root systems using Eco Complete, Flora Base, SMS and SAPS over the Fluorite, gravel, and sand, but I'm not growing the plants to see larger root systems. Larger root systems would probably be more beneficial if you are relying on the substrate and fish waste as the only source of fertilization for the plants but it isn't as important if you add fertilizers to the water column.
In my opinion, substrate choice is a choice of aesthetics over anything else. Do you prefer to have a certain color over another? I prefer black substrates so that excludes Aqua Soil though I plan on giving it a try when I set up my next tank. Do you prefer to have a similar grain size or do you want a more natural look that a varied grain size will give you? Aqua Soil, SMS, and Sand are very similar in size while Eco Complete, Fluorite, and SAPS have a varied grain size. Appearance takes priority over everything else in my tanks...after all, I am the one that has to look at my tank every day
Concerning the pricing of Eco Complete and Aqua Soil, they are very similar in price. You would need six 20lb bags of Eco Complete for a 3" substrate in a 75g tank. That would be about $132 (currently $21.99 at Fosters & Smith) plus shipping. I believe you would need four 9L bags of Aqua Soil for a 3" deep substrate in a 75g tank, which would cost $112 (currently $28 at ADG) plus shipping. Even if you need a fifth bag of Aqua Soil, the price is still very close. There isn't a big difference in price unless you choose to add some of the ADA substrate enhancers and Power Sand along with the Aqua Soil and I don't think most people use those additives. That said, I do believe most of the other ADA products (filters, glass ware, fertilizers, etc) are very high priced in comparison to the other products out there.
For someone new to the planted side of the hobby, I would recommend they start out with Eco Complete or Aqua Soil for a low tech or low to medium light high tech tank. I believe both of these substrates are more forgiving during the initial setup phase of the tank while someone learns the basics of fertilization and CO2 usage.