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Corys and gravel, big deal?

Brandon p

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For years I have been told that you can’t keep corys on gravel. We al know that’s not true because some many people do. I think the issue is not sand or gravel. The issue should be how sharp is the sand or gravel. There are lots of sands that are very sharp and can damage fish. In pest control some sands are so sharp they are used to kill insects by making microscopic cuts in the exoskeleton( if you want more detail message me) I’m going to go ahead an state that o would love to test all this but I’m using information that is common knowledge and fro the manufactures of some products mentioned. 
I going to go right after the big one pool filter sand. So many people use and claim it’s better than gravel for there corys. I can agree that it is better than sharp gravel for corys. However there are many different pool filter sands but most work the same as the silica 

”Silica pool filter sand is the most commonly used type. It's inexpensive, easy to find, and can filter particles down to 20 microns, which is approximately 0.0008 inches. Silica sand is made with ground quartz, and it has rough edges to help trap particulates”. 

Rough edges. Rough edges are what people trying to get away from,correct? Do you want your corys digging and playing in rough edges. 
Zeolite offen used as pool filter sand, here is a  microscopic photo of a piece of zeolite.6ADE7794-9659-479A-A24E-B2A430F5B326.jpeg.9ff04835c074eb4e4d8728fb54a46c1f.jpegThere are several other types of pool filter”sand” like glass. Which speaks on its own. There is the thing pool filter sand works because it is sharp/rough. That’s how it grabs all the gunk from you pool. 
it’s not just pool filter sand lots of sand are sharp. Carbisea even has some of the sand that is sharp. There are great sands to use. 


Gravel is normally easier to determine it it’s sharp. You can feel and see gravel to tell. One super popular “gravel” eco- complete is sharp. Most river style rock is not because it has been rounded of over time by water. 

I’m writing this because I’m a little frustrated with every time the questions gets asked is it ok to put my Cory on gravel I hear no. Then almost inevitably the next thing is pool filter sand is better. It’s not better than round stones(the smaller the round stones the better). If you want to tell people sand is better I’m ok with that but at least learn a smooth sand so you can tell people the right thing. 
 Corys are great fish and have basically lived on all substrates over the years. I have had corys over 30 years mostly on round gravel, but some on sand and now even coal slag. I have not had a fish that has lots barrels in gravel or sand. I think this an over blown topic

 I have seen people try to basically redo there tank or say you should not have corys because that have gravel in the tank.  

@Zenzocan you please read this to make sure it’s ok to write as I know it may upset some people. I’m not worried about that but I do not want to lose any privileges I have here.

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I currently have a community tank with 6 Panda Corydoras on natural gravel. it's almost like tiny pea pebbles.- rounded with no sharp edges. They seem fine. No issues. They don't really 'root' around in it but are constantly cleaning it like little vacuums. I get next to nothing when I gravel vac once a week. I've heard that they did better with sand, but I was old by so many people who had heir corys on gravel that they were fine and I've found it to be the case, at least with mine.

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