Planted Tank Substrate...What is the Best?

[OldFishKeeper]

What's a good substrate for a 75 planted tank? My years old Controsoil base has turned to mud and plants (Amazon Swords, Jungle and Corkscrew Val) are not growing like they did.

I have 8.0 ph and can use CO2 with a controller. What do you suggests for a tank housing tetras and rasboras? I am thinking organic potting soil topped with sand of some sort. Thoughts?

 

[WhistlingBadger]

1" of organic potting soil topped with 2" of sand used to be my go-to substrate, and it works. Soil has its disadvantages, though. It will release ammonia for a few weeks. (I used this to cycle my tanks) If you have any burrowing fish, my good heavens they'll make a mess. And after a year, maybe two, the nutrients in the soil tend to give out and you'll end up adding fert tabs anyway. So, despite my appreciation of the naturalness of it, and the initial boost it gives the plants (it seems to release a lot of CO2 in the early stages, too), I've decided it probably isn't worth the trouble.

These days I just use 2-3" of plain, un-rinsed play sand. The dust settles out after a couple of days, and I like to think it provides the plants with some nutrients. Then I add root tabs as needed. For swords and other heavy root feeders, every 3-4 months seems sufficient.

 

[OldFishKeeper]

1" of organic potting soil topped with 2" of sand used to be my go-to substrate, and it works. Soil has its disadvantages, though. It will release ammonia for a few weeks. (I used this to cycle my tanks) If you have any burrowing fish, my good heavens they'll make a mess. And after a year, maybe two, the nutrients in the soil tend to give out and you'll end up adding fert tabs anyway. So, despite my appreciation of the naturalness of it, and the initial boost it gives the plants (it seems to release a lot of CO2 in the early stages, too), I've decided it probably isn't worth the trouble.

These days I just use 2-3" of plain, un-rinsed play sand. The dust settles out after a couple of days, and I like to think it provides the plants with some nutrients. Then I add root tabs as needed. For swords and other heavy root feeders, every 3-4 months seems sufficient.

Sounds like a reasonable (inexpensive) solution to me. I have a few bags of clay-based gravel that was all the rage back in the early 2000s. I might throw them in for the base, then add the play sand and root tabs.

What play sand do you recommend? I heard that pond filter sand is better...looking for recommendations.

 

[WhistlingBadger]

I usually use play sand from the hardware store. I think "quickcrete" is the name. I've also used "black diamond" and similar blasting sand. Some people say it's too sharp to use with bottom feeders. In my experience, both cories and loaches can live on it for years with no adverse effects. Your mileage may vary. I've never tried pool filter sand, but I hear good things about it.

The safest option, of course, is to get something specifically made for aquariums. But most people seem to like ordinary play or filter sand, and it is far less expensive.

Edit: I just took a look on amazon. "Black beauty" is the blasting sand I've used. I notice that now it isn't a lot cheaper than black sand that is actually made for aquariums, so I'd probably just get some aquarium sand if I wanted something colored.

 

[Colin_T]

sand or gravel

don't waste your time with plant substrates

 

[jaylach]

I've never personally used soil in a tank but, from everything I've read, it is more problem than good. Sand or smooth gravel is probably the way to go.

 

[OldFishKeeper]

sand or gravel

don't waste your time with plant substrates

Right, just jump into hydroponics

 

[noahm]

I've never personally used soil in a tank but, from everything I've read, it is more problem than good. Sand or smooth gravel is probably the way to go.

Part of the problem with a lot of the use of "soil" and the experiences thereof is the poor understanding of soil and what is required. Garden soil sold in most stores is just ground up and composted (barely) mulch (sometimes hardwood tree chips, sometimes bark, sometimes pine mulch), with sand added. There is almost nothing that would be considered actual soil available, and even certain brands that used to be one way are constantly shifting the source material based on supplier. It's a mess. All of that light organic matter is usually barely composted and has no clay or silt particles to hold nutrients long-term and the poorly composted organic matter winds up tying up beneficial bacteria for a long time while releasing who knows what from whatever trees the stuff was made from.

Most people would be better off using riverbottom sandy loam or silty loam (as in dirt right next to a river or stream) if going the dirted route. It's got some small clay content that can hold/bind far more nutrients that other particles (think perpetual nutrient storage), but has the sand and organics that make for a good long term structure. It can just be dug up near the shore and left in a container to dry out and sterilize it a bit if desired, or just used with whatever is in it (highly unlikely to have fish harming critters). I'm not into sterilizing, but a light baking at 175-200 F for an hour or so should do the trick without altering the chemical structure.

There is a simple test that soil scientists often use to get a rough idea of the soil type called the "spit test". Take a little soil, spit in your hand and rub it in a circle with your finger. You will be able to tell if there is sand, clay will feel slippery, and silt is somewhere in-between. Organic matter will be left sort of "floating out" as dark particles. It's a crude, but effective test with a little experience.

The point is, there is a mixed bag of experiences with dirted largely because there is no consistency or understanding of the dirt itself. I would never use bagged "soil" except to modify existing soil that was lacking in organic matter or to help with pH. A bit of peat moss will help with acidification and adding organic matter to high clay soil. Additionally, mixing sand into a clay soil (dry the soil first) will make a more desirable type.

Dirt isn't for everyone, but it's certainly a very good long-term substrate (with cap of course). Somebody should write a proper book about just the dirt part of all of this.

Edit: added some details about sterilizing and soil components.

 

[OldFishKeeper]

Part of the problem with a lot of the use of "soil" and the experiences thereof is the poor understanding of soil and what is required. Garden soil sold in most stores is just ground up and composted (barely) mulch (sometimes hardwood tree chips, sometimes bark, sometimes pine mulch), with sand added. There is almost nothing that would be considered actual soil available, and even certain brands that used to be one way are constantly shifting the source material based on supplier. It's a mess. All of that light organic matter is usually barely composted and has no clay or silt particles to hold nutrients long-term and the poorly composted organic matter winds up tying up beneficial bacteria for a long time while releasing who knows what from whatever trees the stuff was made from.

Most people would be better off using riverbottom sandy loam or silty loam (as in dirt right next to a river or stream) if going the dirted route. It's got some small clay content that can hold/bind far more nutrients that other particles (think perpetual nutrient storage), but has the sand and organics that make for a good long term structure. It can just be dug up near the shore and left in a container to dry out and sterilize it a bit if desired, or just used with whatever is in it (highly unlikely to have fish harming critters). I'm not into sterilizing, but a light baking at 175-200 for an hour should do the trick without altering the chemical structure.

There is a simple test that soil scientists often use to get a rough idea of the soil type called the "spit test". Take a little soil, spit in your hand and rub it in a circle with your finger. You will be able to tell if there is sand, clay will feel slippery, and silt is somewhere in-between. Organic matter will be left sort of "floating out" as dark particles. It's a crude, but effective test with a little experience.

The point is, there is a mixed bag of experiences with dirted largely because there is no consistency or understanding of the dirt itself. I would never use bagged "soil" except to modify existing soil that was lacking in organic matter or to help with pH. A bit of peat moss will help with acidification and adding organic matter to high clay soil. Additionally, mixing sand into a clay soil (dry the soil first) will make a more desirable type.

Dirt isn't for everyone, but it's certainly a very good long-term substrate (with cap of course). Somebody should write a proper book about just the dirt part of all of this.

I have to agree with this. I recently purchased a small bag of "Organic Potting Soil" to experiment with.

To my surprise, it has the consistency of ground up tree bark. It had no characteristics of actual soil. It had to be covered with sand or gravel to prevent it from floating on the surface of the tank.

I would be better off using the adobe clay in my yard!

I have heard some good things about DynaDirt Aquatic Planting Soil. Before I redo my 75 gallon, I will try laterite and some of this topped with sand. I will put this in some pots with plants and see how they fair in some small tanks.

 

[WhistlingBadger]

I've had good luck with Miracle Grow Organic, as well as just normal dirt dug up from the yard. Use proper precautions, of course.