Substrate depth for planted tank

Scleropages · Post by **Scleropages** » 14 Jun 2012, 14:07

For those of you who have planted aquariums, how deep is your substrate?

Bas Pels · Post by **Bas Pels** » 14 Jun 2012, 15:34

on average, 3 - 5 cm

I got tanks with 2-3 cm sand, where I planted some Saggitaria. Now I need to get these plants out, as they became far too much. Odd, as I provide little light, and the substrate is not rich

But most have more sand. Easier planting, after all

2wheelsx2 · Post by **2wheelsx2** » 14 Jun 2012, 16:22

For my CO2 injected tanks with ADA or other fracted clay substrates I have as much as 20 cm of substrate in the back to build a slope for depth and around 5 cm in the front. In my low tech non-CO2 tanks, I have as little as 1 cm of inert Estes sand

dw1305 · Post by **dw1305** » 14 Jun 2012, 19:43

Hi all,

on average, 3 - 5 cm

Same for me, mainly silica sand, or sand and fine gravel, with a small amount of clay and leaf mould (~ 5% of each). I've one small tank with "Tesco lightweight non-clumping cat litter" (calcined moler clay ~ 90% diatomite).

You don't need a huge depth of substrate for plants, even alleged "heavy root feeders" like Cryptocoryne and Echinodorus spp. will get most of their nutrients from the water column.

cheers Darrel

isellcars · Post by **isellcars** » 15 Jun 2012, 06:53

I have a flourite substrate that is about 3-4" deep in my tank. I have lots of stem plants so I need it to be pretty deep.

Bas Pels · Post by **Bas Pels** » 15 Jun 2012, 07:42

dw1305 wrote:You don't need a huge depth of substrate for plants, even alleged "heavy root feeders"

That's right. The Sagittaria I mentioned standing in 2 or 3 cm sand are closely related to Echionodorus - and thrive

Scleropages · Post by **Scleropages** » 16 Jun 2012, 00:11

Thanks for your answers. I have a planted tank with a substrate depth of 1-2cm and I wonder if it would benefit the plants (Crypts & Java fern, mostly) for it to be more like 3-4cm. I have plenty of extra substrate--I just don't want to add more than the plants need--easier to keep clean with less.

wet-handed · Post by **wet-handed** » 16 Jun 2012, 07:00

Like any potted plant the bigger the bucket, more all around growth. If it is heavily planted or plants close together the roots will intertwine with each other, wich is usually ok an compete for nutrients. Most plants are root feeders an get little from the water column. They do get their co2 from the H2O column an that is their main nutrient.but a quick fix for inert substrate or "shallow" is root tabs or fert tablets u put in the substrate the new big thing with planted tanks is real organic potting soil an dosing nothing but little CO2 and decent lighting

Bas Pels · Post by **Bas Pels** » 16 Jun 2012, 08:59

Java fern should not be placed in the substrate - so don't bother about that

Cryptos - it's been over 15 year since I had them (or more) - don't like to be disturbed, but they do like a rich substrate

you might want to put some clay (enrichted with some iron) near them: no distubing, but their roots will be able to reach the nutrients

scientist0724 · Post by **scientist0724** » 16 Jun 2012, 22:03

All my tanks are planted with a plant substrate with the exception of my African cichlid tank which only has pool filter sand, but even that one has some Java ferns attached to lace rocks.

Most of my tanks have anywhere from 3 to 5 inches of substrate. I use Eco-Complete for my community tank, ADA AquaSoil and Fluval Stratum for my shrimp tanks and a laterite/flourite mix for my pleco and cory tanks. It's all dependent on the type of plants that I have.

Arlene

dw1305 · Post by **dw1305** » 18 Jun 2012, 03:16

Hi all,

Like any potted plant the bigger the bucket, more all around growth. If it is heavily planted or plants close together the roots will intertwine with each other, wich is usually ok an compete for nutrients

This is very true, and if you have plants like Echinodorus bleheri or Cryptocoryne balansae their roots will soon permeate all of even a thick substrate.

Most plants are root feeders an get little from the water column

isn't, you can grow Echinodorus, Crytocoryne etc perfectly well without any substrate. You only have to look at the potential growth rate of plants which aren't rooted in the substrate like Amazon Frogbit (Limnobium), Indian Fern (Ceratopteris) and Coon-tail/Horn-wort (Ceratophyllum), as well as the Green Algae (Chlorophyta) (which are ancestral to the Higher plants and have the same physiology & photosystems) to know that foliar uptake is sufficient for plant growth. If you have a look on a forum like UKAPS you will see loads of examples of luxuriant growth in tanks with a sand substrate and EI feeding.

They do get their co2 from the H2O column an that is their main nutrient

Increasing the level of CO2 in the water column will increase plant growth if PAR and macro/micro nutrient levels aren't limiting. Light (PAR) is the factor that governs the productivity of the system. Personally I wouldn't recommend to any-one to go down the CO2 route with rheophilic fish, and faster plant growth vs. the risk of gassing your fish isn't an equation that ever works for me.

A thicker substrate with added nutrients and some CEC will make your plants grow more quickly, but it isn't necessary. This is a tank with a thin sand substrate and low nutrient levels, and Echinodorus, Aponogeton and Crytocorynes, as well as epiphytic Java Fern and Anubias all do well in it.

.

cheers Darrel

Scleropages · Post by **Scleropages** » 18 Jun 2012, 03:40

Darrel, that's some lush plant growth you got there. As Borat says, verrrrnice. If you don't mind sharing, what are the tank's dimensions and what type of lighting do you have on it?

Also, when you write "thick" and "thin" to describe substrate depth, how thick or thin? Can you give some approximate measurements?

dw1305 · Post by **dw1305** » 18 Jun 2012, 09:52

Hi all,

If you don't mind sharing, what are the tank's dimensions and what type of lighting do you have on it? Also, when you write "thick" and "thin" to describe substrate depth, how thick or thin? Can you give some approximate measurements?

That is a standard 24" x 12" x 15" (60cm x 30cm x 38cm length, width, height), so about 15 gallons. There is about 2cm of silica pool filter sand, and a very small amount of cat litter following an accident with a some planters.

The lighting is 2 x 14W 6500K T5 (with reflectors) and it gets quite a lot of indirect light through the window (it has a backing but both end panels are open). It is in the back of the teaching lab.

cheers Darrel

Scleropages · Post by **Scleropages** » 20 Jun 2012, 18:35

Thanks for your help, everyone. I think I am going to add another cm of substrate to my tank--a 45gal (36" x 12" x 24").

I have fertilizer pellets but don't add them much because I think the plant growth is mainly limited by my current available lighting. Right now, I have one Coralife 96 watt 6700K compact fluorescent lamp, which I estimate (after some shoddy google research) puts out 8000 lumens when new. For the depth of the tank, I am definitely looking to add more lamps.

I'll probably get another one of the same unless anyone can convince me to go with an alternative to the 96watt 6700K compact fluo bulb. Is there an LED system that puts out the same or more lumens and is relatively inexpensive?

2wheelsx2 · Post by **2wheelsx2** » 20 Jun 2012, 18:51

Scleropages wrote:Thanks for your help, everyone. I think I am going to add another cm of substrate to my tank--a 45gal (36" x 12" x 24").

I have fertilizer pellets but don't add them much because I think the plant growth is mainly limited by my current available lighting. Right now, I have one Coralife 96 watt 6700K compact fluorescent lamp, which I estimate (after some google research) puts out 8000 lumens when new. For the depth of the tank, I am definitely looking to add more lamps.

I'll probably get another one of the same unless anyone can convince me to go with an alternative to the 96watt 6700K compact fluo bulb. Is there an LED system that puts out the same or more lumens and is relatively inexpensive?

That's more than enough light for a 45 gallon tank of those dimensions. Adding more light without available carbon is just going to grow algae and not the plants. I can almost guarantee that your plant growth is not limited by light in your setting with a 96 W PC light. I am growing plenty of low light plants (Subwassertang, moss, Anubias, Stargrass and even Blyxa Japonica and Alternathera reineckii in my 20 gallon with Florabase and 3 watts of low output LED. The difference is that I add glute in the form of Metricide 14. Not a single spot of algae. And growth is slow which is exactly the way I want it as this is my growout tank for young plecos....the plants are to help with waste uptake so I don't have to do 5 wc a week to deal with the more frequent feedings.

Scleropages · Post by **Scleropages** » 21 Jun 2012, 00:50

One other thing I've been thinking about regarding my tank are the airstones. I have had two airstones running continuously in it (one as part of a large sponge filter) since I set up the tank a few years ago. I wonder if the plants would do better without them. I also have an Eheim canister filter on that tank, so no worries regarding filter capacity.

I removed the airstones today and will arrange all of my java fern off the substrate and anchor it on the driftwood. Will take a pic or two to share when I get a chance. I'm hoping to breed the Sturisoma sp. I have in there at some point. It looks like I've got one male and two females. I've been doing water changes with rainwater. I collected ~100 gallons about a week ago off one of the drainpipes on my house.

2wheelsx2 · Post by **2wheelsx2** » 21 Jun 2012, 01:04

Scleropages wrote:One other thing I've been thinking about regarding my tank are the airstones. I have had two airstones running continuously in it (one as part of a large sponge filter) since I set up the tank a few years ago. I wonder if the plants would do better without them. I also have an Eheim canister filter on that tank, so no worries regarding filter capacity.

It's a bit complex to answer depending on your setup, but in general no. With the airstones in a non-CO2 injected, you're able to introduce CO2 from the atmosphere since it's not saturated in the tank. But you achieve the same with sufficent surface agitation. And it would maximum the O2 in the water also, which is also a good thing, for the fish and the plants especially at night.

Scleropages · Post by **Scleropages** » 21 Jun 2012, 02:57

2wheelsx2 wrote:
Scleropages wrote:I wonder if the plants would do better without them (airstones).
It's a bit complex to answer depending on your setup, but in general no.

Just so I understand, you are saying that you think plants in a non-CO2-injected tank will do better with an airstone than without?

2wheelsx2 · Post by **2wheelsx2** » 21 Jun 2012, 04:44

Scleropages wrote:Just so I understand, you are saying that you think plants in a non-CO2-injected tank will do better with an airstone than without?

Not specifically an airstone, but whatever maximizes the gas exchange between aqueous and atmospheric gases since CO2 is only supplied by the fauna in the tank. With adequate surface agitation, the gases available in the air can be utilized as a continuous supply.

Scleropages · Post by **Scleropages** » 21 Jun 2012, 11:19

That's what I thought you meant. Just wanted to clarify. Thanks.

I added about 20 more lbs. of substrate to the tank. I'm using Kahuna Soil by Carib Sea. Will rearrange the java fern and anchor it all onto the driftwood today during a water change. I'll try to take some pics tonight.

dw1305 · Post by **dw1305** » 21 Jun 2012, 14:04

Hi all,
Keep the air-stones.

Just so I understand, you are saying that you think plants in a non-CO2-injected tank will do better with an airstone than without?......Not specifically an airstone, but whatever maximizes the gas exchange between aqueous and atmospheric gases since CO2 is only supplied by the fauna in the tank. With adequate surface agitation, the gases available in the air can be utilized as a continuous supply.

This is a very good point, lots of people think that they have to reduce surface agitation in a planted tank, but as "2wheelsx2" has pointed out, if you don't add CO2, the more surface turbulence and gas exchange you have the better.

This is the reason why "wet and dry" trickle filters are so effective, they have a huge gas exchange surface. The important word here is "exchange", gases will diffuse both in and out along their concentration gradients at the air-water interface, and both oxygen and CO2 will constantly be replenished (or out-gassed) along this concentration gradient with the atmosphere.

cheers Darrel

Scleropages · Post by **Scleropages** » 21 Jun 2012, 16:44

Indeed. Anything that mechanically increases exchange of atmospheric gases in your water will usually benefit the whole biocycle. As I have no plans for adding CO2, I will put the airstones back in. A lot of new substrate floating in the tank this morning. The airstones will help sink 'em. Exchange is a wonderful thing...