# Keeping sand clean.



## Sarpijk (12 Jan 2022)

Hi all, I have used the same sand on top of potting soil in two scapes. In the first Scape which has been running for two years the sand stays perfectly clean. On the second scape, a paludarium running for no more than a month the sand gets dirty with organic material and looks unsightly.









Some key points to discuss.

1. Does it make any difference if the substrate is more mature?

2. Could a few pygmy corys that are kept in the first tank have all this impact?

In both tanks the filtration is not strong. In the first tank I have a small Aquaclear HOB and in the paludarium a small pump. Circulation is minimal in both cases.


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## Hufsa (12 Jan 2022)

Is the stocking the same in both tanks? I see a lot of _ahem_ turds in the second picture


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## Sarpijk (12 Jan 2022)

In the first tank I keep 4 pygmy cories, around 20 rcs and many snails both Ramshorns and Malaysian trumpets.

In the other tank there only a few Ramshorns and two rcs.


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## arcturus (12 Jan 2022)

In the second tank, where is the organic detritus coming from ? From the photo it looks like uneaten food, fish excrement, or that several plants melted or dropped leaves and you have not cleaned the tank. In any case, that tank has virtually no livestock, no mechanical filtration, and low water circulation. That detritus is not going anywhere anytime soon without maintenance...



Sarpijk said:


> 1. Does it make any difference if the substrate is more mature?
> 2. Could a few pygmy corys that are kept in the first tank have all this impact?
> In both tanks the filtration is not strong. In the first tank I have a small Aquaclear HOB and in the paludarium a small pump. Circulation is minimal in both cases.


I think you are underestimating (1) the impact of the HOB filter in terms of mechanical filtration and water circulation, (2) the role of bacteria in a mature tank in terms of decomposing organic matter.


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## Sarpijk (12 Jan 2022)

arcturus said:


> In the second tank, where is the organic detritus coming from ? From the photo it looks like uneaten food, fish excrement, or that several plants melted or dropped leaves and you have not cleaned the tank. In any case, that tank has virtually no livestock, no mechanical filtration, and low water circulation. That detritus is not going anywhere anytime soon without maintenance...
> 
> 
> I think you are underestimating (1) the impact of the HOB filter in terms of mechanical filtration and water circulation, (2) the role of bacteria in a mature tank in terms of decomposing organic matter.


As soon as I clean it the detritus comes back again. I use an airline tube to vacuum the small particles. The organic material comes as you have correctly guessed from plants melting, some spagmum moss I have used on the emersed part and some uneaten food from the shrimp.

I do not underestimate the contribution of the HOB filter although as I mentioned there is no visible circulation.

I have already mentioned there are lots of Malaysian trumpet snails in the first mature tank. Here's another pic, I have just dropped a shrimp pellet. Could they be cleaning the sand along with the cories?


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## arcturus (12 Jan 2022)

Sarpijk said:


> As soon as I clean it the detritus comes back again. I use an airline tube to vacuum the small particles. The organic material comes as you have correctly guessed from plants melting, some spagmum moss I have used on the emersed part and some uneaten food from the shrimp.
> 
> I do not underestimate the contribution of the HOB filter although as I mentioned there is no visible circulation.


There will be circulation even if not visible. Even a small filter should be moving at least 100-200 l/h which will help removing suspended matter from the water column.



Sarpijk said:


> I have already mentioned there are lots of Malaysian trumpet snails in the first mature tank. Here's another pic, I have just dropped a shrimp pellet. Could they be cleaning the sand along with the cories?


The snails do feed on decaying organic matter. But if you add snails and keep those levels of sediment you will end up with a tank covered in snails. Meanwhile, I would keep manually removing those plant remains and sediment to avoid having to deal with NH3 and NH4 spikes.


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## Sarpijk (12 Jan 2022)

Thanks. I doubt their is any ammonia or nitrites because the water surface is covered with Limnobium not to mention the back wall is a big sponge with mosses and plants attached so all this should work as a filter.

I have put two red cherries and after 4 days they are still alive and healthy. 
I will vacuum again to manually remove the detritus as advised. 

I mainly wanted to see if the tank would benefit from the addition of some pygmy corydoras.


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## Jaseon (12 Jan 2022)

Do you have snails in your paly? Looks like snail poop to me.

When you say as soon as you clean the crap comes back do you mean the next day or?


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## KRMans (15 Jan 2022)

Sarpijk said:


> I mainly wanted to see if the tank would benefit from the addition of some pygmy corydoras.



What sort of sand did you use? I read that Corydoras are picky in terms of the sand, and that they do not like Pool Filter Sand.


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## PARAGUAY (15 Jan 2022)

I have two sands in the Cory tank Pets@home and Unipac Riversand the Corys keep it clean by movement  .Still need to do maintenance W/C extra but they do a good job IME


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## Sarpijk (15 Jan 2022)

I would put in pygmy cories if it weren't for the small water volume. The tank is exact dimensions of DOOA SYSTEM TERRA 30 and although ADA have used many different fish species in it I doubt it is sufficient for anything really other than shrimp. I have thought about adding Chilli rasboras but haven't decided upon it yet.

The sand is aquarium sand and although it was my first time ever using it the older tank has been one of the most successful yet in terms of plant health.


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## Wookii (15 Jan 2022)

Just transfer over some of your clean up crew from the other tank and I reckon they’re sort it for you.


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## Sarpijk (15 Jan 2022)

Wookii said:


> Just transfer over some of your clean up crew from the other tank and I reckon they’re sort it for you.


I might take you on this since the paludarium seems to be full of detritus worms and other microorganisms that the pygmies would enjoy. The other thing in my mind is to cover the substrate with leaf litter and but a few of micro rasboras.


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## Wookii (15 Jan 2022)

Sarpijk said:


> I might take you on this since the paludarium seems to be full of detritus worms and other microorganisms that the pygmies would enjoy. The other thing in my mind is to cover the substrate with leaf litter and but a few of micro rasboras.



Sorry I meant your shrimp and snails - I’d say it’s too small for fish at 10 litres.


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## _Maq_ (12 Jul 2022)

Sarpijk said:


> On the second scape, a paludarium running for no more than a month the sand gets dirty with organic material and looks unsightly.
> Some key points to discuss.
> 1. Does it make any difference if the substrate is more mature?
> 2. Could a few pygmy corys that are kept in the first tank have all this impact?
> In both tanks the filtration is not strong. In the first tank I have a small Aquaclear HOB and in the paludarium a small pump. Circulation is minimal in both cases.


Neither filtration nor Corys.
It's the microbes you need. Microbes need roughly the same nutrition as plants do, as well as oxygen. I'm observing detritus carefully for years. If it remains in place for exceedingly long time, I believe the microbes suffer from some kind of nutrition imbalance. (Just like the Helantium or what is it on your pic.) Feces are usually rich in carbon but less so in nitrogen. If nitrogen is the limiting element microbes would not hurry to feed on nitrogen-poor food. That's just one of possible imbalances, though.


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## erwin123 (13 Jul 2022)

Just came across this in Oliver Knott's FB


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