Bonsai's and Planted tanks ??
By Rob Charite, June 2002

First of all let me remind you that all tank substrate isn't permanent !! No matter what books say . It wont last for ever..
Having said all of this i can finally start with my story :)
Bonsais are often called bonsai trees ( which is an incorrect name) and planted tanks. What do they have in common ?? Not much you would say :) More than you think I would say. Now since this is a Discus forum I would limit my self to the discus habitat and rule out all Dutch Tank priciples.
Ok back to the story :) Bonsai are root feeders and have no other means to gain their food than by the root. Pretty much like the swamp plants we use in our biotope tanks.
A South American biotope tank is almost equal to the Echinadorus sp. and soft water. So let's concentrate on root feeders in the tank. Actually these types of plants are more used to life above the surface but can cope with submerged situations with one restriction :) they need wet feet :) Who doesn't know the Spatiphyllum sp. in their living rooms :) the one with the cute white flowers :) its often the only plant that does quiet well in a living room with way to much water just because its a swamp plant :)

Bonsai trees, especially the older ones, don't cope so well with major changes due to the restrictions they have. F.I. small pot and a lot of trimming thus we keep the plant in shape by teasing and manipulating nature. For that we need a healthy growth.
Healthy growth means nutrition and light in the proper amounts. The less we change in the given situation the better the chance is the plants or trees for that matter will thrive. So we could fairly say that we don't want to fiddle to much with the roots but don't want a food shortage as well.

We don't want all the nutrients in our water column but want plants to thrive for the benefit of our beloved tanks and fish. This is all common sense and there is much written about that :) How to achieve that goal ??

Mainly by seeing to it we have a good plant base or substrate. One of the things we often forget is the fact that the upper layer is just there to polish the viewing and to keep the nutritional layer where its supposed to, at the bottom of the tank not in the tank. Don't underestimate the importance of a good base !! it determines your success with plants and fish !! of course there are enough people who say it works fine with just sand but we don't see what they do to keep it that way .

So staring from that point of view I would say better safe than sorry.

Okidoki back to the substrate.

We have seen heard it all :) words like gravel, peat, sand, clay. Sometimes used in combination sometimes not.

To recap a bit: Peat moss is the ideal stuff for lowering hardness which is important for the plants diffusion creating an almost perfect osmotic pressure difference aorund the roots, Clay is the perfect stuff for slowly releasing nutrients which it holds especially iron, Sand not a good nutrient surplier but ideal for weight and density, Dito for gravel. Be aware that the thicker the individual granule size is the thicker the top layer must be for preventing nutrient leaching into the water column.

Now Comes the plan :) we combine all !!!!! Indeed we mix clay, sand and peat together !! What??? that's living room plant soil !!! it tends to rot and "pollutes" the water column !!! major WRONG !!!!!!!!!!! It's the amount of every ingredient that counts. Indeed normal potting soil contains a lot of peat and somewhat less clay and sand or no clay and just a twist of sand.

They use a lot of peat in the mixture to see to it that normal plants have enough soft water available. Tap water is often too hard and when we add that to our soil the amount of salts is higher outside the plant than in the plant. Result ?? Certain death due to "reversed" osmotic pressure!!!

That's why it is easier to make our tank mixture on our own :)

How to acomplish this ?? Right!!! we use Bonsai tree mixture :)

The best general bonsai mixture is 40 % sand, 40 % clay and 20 % peat :)

Now if that ain't gonna be an ideal bottom layer for our planted tank nothing will be :) All the advantages gathered in one mix :) All we have to do is add it in the tank and provide a big top layer :) bigger with gravel :) And the plants thrive with the advantage of adding no nutrients in the water, but depending on the amount of plants, if we have to refertilise no adding stuff in the water but place it right where its needed !!

So we brew the same mixture, roll it in kitchen towel (paper one) making pellets of about half an inch and insert them near the root system Where exactly ?? if whe didn't prune the plants, the right place for adding nutrients is exaclty the spot where the roots end or begin, what ever you prefer :) Now visualise the tip of the leaf and imagine a straight line to the gravel :) that's exactly the right spot :)

Don't forget that no substrate last for ever !!

Its almost a holy rule for the benefit of plants and fish :)

Completely replace the substrate every 2 or 3 years and you won't have any problems

greetz Rob Charite