Gravel and out!

[Ram419]

Hello. Nitrate levels depend on the amount of water you're changing and not aquatic plants or the bottom material. As for vacuuming, everything in the tank dissolves, so by just removing and replacing water, your remove whatever has dissolved in it, including fish and plant waste material. So, you don't really need to vacuum unless you like doing that sort of thing.

10 Tanks (Now 11)

This is not true, at least not with the experince I've had with the gravel substrates I was using (Rock and pebbles). I've done testing of the water before and after adding the sand and there is a signifcant difference of lower nitrates after adding sand. There are smaller gravel substrates that work better then the rock and pebbles, I will agree on that.

 

[10 Tanks]

This is not true, at least not with the experince I've had with the gravel substrates I was using (Rock and pebbles). I've done testing of the water before and after adding the sand and there is a signifcant difference of lower nitrates after adding sand. There are smaller gravel substrates that work better then the rock and pebbles, I will agree on that.

Hello again. You can certainly use whatever bottom material suits you. However, the bottom material of sand or gravel or pebbles has no affect on the nitrogen in the tank water. These neither make nitrogen, nor will they remove it. This level depends on the living things in the tank that make it. In other words the fish, snails and the plants. The only means of removing the nitrogen is to change out the tank water.

10 Tanks (Now 11)

 

[Uberhoust]

I have used most types of substrate at one time or another, and I will have to say I still like gravel for some applications and sand for others.

There are some miss conceptions and specific aspects that are not considered.

1. Gravel in most other disciplines starts at 2mm average grain size up to >50 mm
2. Sand typically starts at 2mm and goes down as far as .06 mm
3. The porosity of the substrate depends not only on the average size of the particles but also on the range of particle size. A large variation of particle sizes significantly reduces the porosity of the substrate. Low variation of particle sizes increases the porosity of the substrate.
4. The overall porosity is greater with larger particles than smaller ones but can be influenced as above by the range of sizes, a gravel with high variability in particles could end up with less porosity than a sand substrate with uniform particles.
5. Porosity affects the migration of waste, and oxygen through the substrate, more porosity means the waste gets deeper sooner, and also means more waste can be trapped, but it is also easier to remove. On the other hand less porosity means that less oxygen can be transported with the water and can lead to anoxic conditions, and the generation of H2S. Generally the more porosity the deeper the waste can go but also the deeper the aerobic bacteria can live effectively breaking down the waste.
6. Larger particles settle sooner. This is mostly a consideration for people with a HOB filter, because the filter impeller is before the filtration proper and when you get into finer sands this material can get caught between the impeller drive housing and the permanent magnet on the impeller, and between the permanent magnet and the spindle, causing wear and binding. Most canister filters have the drive after the filter and intank sponge filters really don't care.
7. Most sands and gravel are inert, silica based, but some have some unique characters, seachem Florite is partially magnetic, aragonite increases GH, KH, and obviously pH. Sand with magnetic particles is particularly bad for HOB filters because it is difficult to remove from the impeller drives.
8. Regardless of particle size the abrasiveness of the substrate is primarily determined by the angularity of the particles, a smooth pea gravel will damage fins and skin of the fish less than a highly angular sand such as construction sand created by crushing rock.

Overall there is, in my opinion, nothing fundamentally wrong with gravel or sand they both have been used successfully for years, and will continue to do so. Some flora and fauna might do better in one than the other, but this shouldn't mean that one or the other is overall a bad choice. The choice should be made one what works for you and your plants and animals. I currently have one tank with gravel, 1/8 inch to 1/16 inch (3.5mm to 1.5mm), which has been my personal size of choice for years. And, one tank with sand 0.2 mm to 1mm which is heavily screened (I screened it) play sand. Both seem to work for me.

 

[Ram419]

Hello again. You can certainly use whatever bottom material suits you. However, the bottom material of sand or gravel or pebbles has no affect on the nitrogen in the tank water. These neither make nitrogen, nor will they remove it. This level depends on the living things in the tank that make it. In other words the fish, snails and the plants. The only means of removing the nitrogen is to change out the tank water.

10 Tanks (Now 11)

Not sure, all I can tell you is what I saw. There weren't really any other factors changed other then the added sand that helped keep the nitrate levels lower at the time. And this was done on two different tanks at the same time ( 20 gallon and a 55 gallon ). Both had much lower nitrates build up over time after adding the sand to it.

 

[Byron]

Not sure, all I can tell you is what I saw. There weren't really any other factors changed other then the added sand that helped keep the nitrate levels lower at the time. And this was done on two different tanks at the same time ( 20 gallon and a 55 gallon ). Both had much lower nitrates build up over time after adding the sand to it.

The explanation is most likely that the waste consuming bacteria live in the substrate primarily, and with sand there is greater surface area. At least that is how it was explained to me some years ago. Keeping nitrates down should be fairly easy if they occur solely within the aquarium and not in the source water to begin with. Many (ot saying you) feed their fish way too much, and what goes in will come out creating pollution and nitrates. Plants, water changes, not overfeeding or overstocking all help. And I believe sand does as well.

 

[Endlersendlers]

This is false. Bacteria require oxygen. Sand does not allow water to circulate, so the bacteria can only populate the surface. Gravel allows water to circulate to several centimeters depth depending on how coarse it is.

Aerobic bacteria require oxygen. Anaerobic bacteria, which include a lot of disease causing bacteria, do not need oxygen and only live in anaerobic (no air) environments. Gravel can have anaerobic pockets too if it’s not getting vacuumed or disturbed. I won’t get into the pros and cons of sand and gravel, though. I just started using sand in a few tanks and am interested to see how it works out.

 

[Genxredhead]

Hello. Nitrate levels depend on the amount of water you're changing and not aquatic plants or the bottom material. As for vacuuming, everything in the tank dissolves, so by just removing and replacing water, your remove whatever has dissolved in it, including fish and plant waste material. So, you don't really need to vacuum unless you like doing that sort of thing.

10 Tanks (Now 11)

Wait! Are you saying the vacuuming is optional?

 

[vince82]

I setup my last tank with a substrate of top soil from home depot mixed with gravel (the idea is that just top soil would be anoxic when wet - think mud).
I bagged it into mesh plastic bags and then I covered the whole thing with coarse sand.
I had to move/replant a crypto, I can tell the roots had gone through the plastic mesh and into the top soil, because it did not want to come up.
However, no gravel has surfaced and it's still looking good.

 

[Endlersendlers]

Wait! Are you saying the vacuuming is optional?

I don’t agree that vacuuming is optional as the detritus and waste sinks into the gravel as it decomposes and otherwise creates anaerobic pockets, where disease causing organisms can be found. When you vacuum, you know how much you get out, it’s not just in the water, and you see how it builds up if you don’t for a while. It takes a really, really long time to break down to where it’s removed with the water, and at that point it’s built up muck in the bottom (think old pond, just a matter of scale) and a sick tank. Can enough and the right types of plants keep this from happening? I’m not sure about that. (If you were just joking, I apologize for telling you what you already knew.)

 

[seangee]

Wait! Are you saying the vacuuming is optional?

I find for sand its not necessary if you have a decent amount of plants, and of course regular water changes. I changed the substrate in this tank in 2019 and it has never been vacuumed.

 

[Ram419]

I definately don't deep clean the sand. Sometime I vaccume the top of it if needed but otherwise it's not needed, unless you are doing gravel only.