Subtrate Suggestion for Freshwater Planted Aquariums

This photo and article was emailed by John Glaeser to members of the MAGC. I am re-posting it here for everyone's benefit.

Aquatic plants get most of their nutrients through their roots. Here's a suggestion:

Bottom Layer: One inch blend of top soil and a little clay, tamped down. (ACE Hardware soil).

Top Layer: Two inches of well rinsed fine gravel (#40 red flint filtration sand/gravel from Soils and Engineering, 1102 Steward St., Madison.... 50 lb bag ~ $16). Some aquarium stores may carry this.

Fine gravel weighs down soil so it doesn't get into water column when introducing plants. Cuttings and rooted plants easily can be pressed down through the fine gravel, deep enough so they barely make contact with soil nutrient depot. When fingers are withdrawn after inserting plant, the fine gravel caves in and seals the gap.

If plants are root fed, one need not add liquid nutrients to water. By keeping nutrient levels low in the water, algae problems are reduced. Plants do pick up some nutrients through their leaves. In a well stocked planted aquarium with fish creating waste, plants take in these resulting nutrients through their leaves, depriving algae of nutrients they need.

Things can get tricky if an aquarium is sparsely planted or contains slow growing species. With a large fish population, algae could happen quickly. With not enough plants to take care of fish waste, more frequent water changes helps reduce nutrient levels. In some cases a shorter photo-period is worth a try, like 5 or 6 hours lights ON. Since algae need light to thrive and since they have a very limited nutrient storage capacity, they cannot survive in longer dark periods, though valued plants can do so.

In a mature soil based setup, there can be problems with water getting cloudy when one removes plants. Having a working siphon aimed at plant extraction site during plant removal, sucks out these loose soil particles.

John