Pot soil base layer question

Ballyhoo

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Jun 27, 2010
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I'm doing a planted 2.5 gal betta tank and I have read that it is possible to do organic potting soil as the base layer of the tank. I planned on doing the soil underneath a layer of sand.

I just wanted to make sure that it works and is safe for tanks.
thank you
 
All potting soils are not the same. There is a large variation in what is used in these mixes. You'll have to read the bag to see what the ingredients are.

A few things to watch out for.

Perlite and Vermiculite - these are used to add drainage and water holding capacity to the mix. Both of these float in water.... I'd avoid these unless you like the look o floating white and golden metallic thingy's in your tank.

Time release fertilizers - These are generally little balls (can be blue, white, green, yellow etc...) that dissolve in water with a pH between 5.0-7.0. These generally contain NH4NO3 as one of the ingredients. These can act as little time release ammonia bombs.

Wetting agents - These are chemicals that are added to higher end potting mixes to decrease the time it takes for the media to become saturated with water. These are generally a type of polymer which can have an unpredictable effect on your fish/inverts.

High percentage bark based media - The pH of this is generally very low. Commercially it is only used with plants that prefer acidic soils.

What to look for in a mix -

Sand- 25-50% sand mixes are generally some of the best. In my greenhouses I use a 25% mix that is heads and shoulders above any other that I've tried.

Sphagnum peat moss- This is harvested from bogs and is partially decomposed. It is slightly acidic but offers excellent nutrient holding capacity for fertilizers.

Other ingredients can include compost (good), rice hulls (float), other clays (many different names, generally good), coconut husks (so-so), etc. Just be sure that you look up all of the ingredients in the bag before you add them to your tank.
 
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I would not recommend using peat. It is too unpredictable, it will likely cause wild swings in water chemistry in a tank this small.

The Walstad method usually recommends potting soil, but personally I would go with topsoil. If you can find an organic topsoil, great, if not you will have to go with a brand like Hyponex - and it won't hurt.

These usually come in 40 lb bags and are very inexpensive, because they don't have stuff like little twigs, sticks, leaves, perlite, moss, bentonite, etc. Which is great for terrestrial plants...but will just float and be messy in an aquarium.

If you only want to get a little bag because you can't use a big bag out in your yard, get an 8 lb bag of Hyponex potting soil. It is just topsoil with perlite, really. Rinse it well to get all the little floating bits (perlite looks like little Styrofoam balls, but it's actually volcanic rock) out...and presto!
 
By the way, if you can find something called Schultz Aquatic Plant Soil, this is great stuff, used to be $8 for a 4 lb bag or so. There is also Schultz Clay Soil Conditioner, I believe it is the same stuff or similar. It also goes by the name of Profile.
 
Are you not considering aquarium substrate because all the 'good stuff' comes in big bags? Try contact Mgamer20o0; I bought a small amount of substrate for a 1.5G tank.
 
Are you not considering aquarium substrate because all the 'good stuff' comes in big bags? Try contact Mgamer20o0; I bought a small amount of substrate for a 1.5G tank.

I was going to do a base layer of soil with gravel on the top.
 
Use top quality soil and check the ingredients.

I usually mix it 50/50 w/sand and cover the bottom of the tank about 1-2'' deep.

On top of the 50/50 sand/soil mix, I put 2'' of sand or gravel.


I have done this in many many tanks, my oldest is about 3 yrs old and the plants are still doing well.
 
Ahh! I have to be a friend and say, "Don't do it!"... :duh:

1) I used Miracle-Gro organic potting soil (recommended by D. Walstad) which has peat in it... my water is perpetually tinted - not too bad but may not be what you want.

2) I used small gravel as a top layer. This made filling very messy and also I think helps the peat to stain the water.

If you do go this route, I think topsoil would be a better choice. Also, top off with pool filter sand. Do not make your soil layer more than 3/4" thick (remember, this is a small tank)... and be generous with your cap/sand layer.

Plant into the soil before you cap with sand - this helps to keep things neat. Place your capping sand in the corners of the tank and around the edges before you start planting (on top of the soil) - this will make filling in with sand cleaner.
 
I have used top soil with flourite topping it, done fine. Not messy as long as you don't removed plants around so much.

I have Miracle-Gro organic potting soil in two of my tanks, one top with sand, the other with flourite. Not messy if again you leave the plants.

So with using either one, you want to make so you have the aqua scape as you want it. Movement of rooted plants will bring the soil to the top when you move them.
 
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