For the cory's how do I know if my gravel is sharp?

[pettygil]

For the cory's how do I know if my gravel is sharp? I picked it up and rubbed against my hand and it did not scratch my hand. So does this mean my gravel is not sharp. The gravel is fine and slips past my fingers while holding the gravel.
I just want to make sure everything is ok for my Cory's. They are quite active and swim in a school. I love Cory's as much as Betta's. Cool fish to watch and enjoy. I was thinking of using sand instead to be on the safe side. What fun that is going to be, to empty out my entire tank, and getting rid of all the gravel. I know it's all my fault I should of done my research, before buying the fish. Is there an easy way to get rid of the gravel? Is very fine and thin gravel.

 

[Rocky998]

Corydoras like sand as a substrate because they will actually sift through the sand with their gills.
Sand is just softer on bottom dwellers, especially when they have barbels. They can get damaged from the gravel.
I've seen some people successfully keep corydoras over gravel BUT generally you want to keep them over a very fine sand

 

[AdoraBelle Dearheart]

@Rocky998 is right, cories do love snuffling their heads through sand, and filter feed when given the opportunity to do so. If you do switch to sand, look for a fine smooth sand. Some larger grains can be sharp edged, and you don't want cories to be trying to filter feed that through their delicate gills.

The other potential issue with gravel isn't that the gravel itself is sharp enough to scratch and damage the barbels. It's that food, poop and other detritus falls down into the gravel and becomes a bed of bacteria, producing mulm, as I'm sure you've seen by now anytime you've gravel vacc-ed the substrate! Mulm itself is harmless, but other, more nasty bacteria can thrive if the gravel isn't cleaned thoroughly enough/often enough, and some corydora keepers and authorities because it may be that bacteria thriving in a gravel substrate is what potentially causes the barbel erosion.

Sand tends to stay cleaner since the detritus doesn't fall down large gaps like in gravel, so the detritus tends to end up in the filter or cleaned from the surface of the substrate manually by the keeper, and with sand you don't have to dig down to the bottom of the tank with the syphon bell, you just swirl the bell end gently an inch or so above the surface of the sand and suck up the muck that way. So while there is still a beneficial bacteria bed in the sand, there is less opportunity for nasty bacteria and pathogens to get established and thrive than there is in a gravel bed.

For those keepers that still use gravel for cories, it's important to keep it clean with weekly substrate cleaning, and live plants are also useful since they make use of the mulm that remains no matter how much someone might try to remove any scrap of dirt. The problems seem to happen most often in tanks that have gravel, fake decor, and maintenance/substrate cleaning hasn't been happening often enough if at all.

Switching out substrate is intimidating, but it's rarely as hard as you think! People here can talk you through simple tricks and methods so you can be prepared in advance, and how to make the process as easy as possible for both you and the fish.

What size is the tank and what's the stocking?

 

[AdoraBelle Dearheart]

Just had a scan back over your post history, when did you get the cories? How many did you get, and any chance of a photo or video of them so we can see which species, please?

Would be good to know, along with the current stocking of the tank they're in, I'm assuming they're in the 20g?

 

[TNG]

What fun that is going to be, to empty out my entire tank, and getting rid of all the gravel. I know it's all my fault I should of done my research, before buying the fish. Is there an easy way to get rid of the gravel? Is very fine and thin gravel.

I wouldn’t empty the tank and remove all the gravel in one go, as doing so could mean removing the beneficial bacteria from the tank (assuming your tank has now cycled).

I’d remove about 50% of the water and scoop out gravel from half the tank, replace it with sand. I’d leave the remaining gravel in the tank for around 3 to 4 weeks to give the beneficial bacteria time to colonise the new sand. Then remove and replace the rest of the gravel. I wouldn’t worry about some gravel remaining in the tank.

The sand should be thoroughly washed or you’d end up with cloudy water.

 

[pettygil]

What size is the tank and what's the stocking?
Size is 20 high

@Rocky998 is right, cories do love snuffling their heads through sand, and filter feed when given the opportunity to do so. If you do switch to sand, look for a fine smooth sand. Some larger grains can be sharp edged, and you don't want cories to be trying to filter feed that through their delicate gills.

The other potential issue with gravel isn't that the gravel itself is sharp enough to scratch and damage the barbels. It's that food, poop and other detritus falls down into the gravel and becomes a bed of bacteria, producing mulm, as I'm sure you've seen by now anytime you've gravel vacc-ed the substrate! Mulm itself is harmless, but other, more nasty bacteria can thrive if the gravel isn't cleaned thoroughly enough/often enough, and some corydora keepers and authorities because it may be that bacteria thriving in a gravel substrate is what potentially causes the barbel erosion.

Sand tends to stay cleaner since the detritus doesn't fall down large gaps like in gravel, so the detritus tends to end up in the filter or cleaned from the surface of the substrate manually by the keeper, and with sand you don't have to dig down to the bottom of the tank with the syphon bell, you just swirl the bell end gently an inch or so above the surface of the sand and suck up the muck that way. So while there is still a beneficial bacteria bed in the sand, there is less opportunity for nasty bacteria and pathogens to get established and thrive than there is in a gravel bed.

For those keepers that still use gravel for cories, it's important to keep it clean with weekly substrate cleaning, and live plants are also useful since they make use of the mulm that remains no matter how much someone might try to remove any scrap of dirt. The problems seem to happen most often in tanks that have gravel, fake decor, and maintenance/substrate cleaning hasn't been happening often enough if at all.

Switching out substrate is intimidating, but it's rarely as hard as you think! People here can talk you through simple tricks and methods so you can be prepared in advance, and how to make the process as easy as possible for both you and the fish.

What size is the tank and what's the stocking?

Size of 20 high. Stocking is 8 Glo Tetra's, 5 Blue spotted cory's. 3 red eyed Tatra's.

 

[pettygil]

Just had a scan back over your post history, when did you get the cories? How many did you get, and any chance of a photo or video of them so we can see which species, please?

Would be good to know, along with the current stocking of the tank they're in, I'm assuming they're in the 20g?

I got the cory's a few days ago. I got 5 Cory's. The type of fish is 5 blue spotted Cory's. I would take a pic but it's blurry. Yes, the fish are in a 20 gallon, I have 5 blue spotted cory's, 3 red eyed Tetra''s, 8 glow fish.

 

[AdoraBelle Dearheart]

I got the cory's a few days ago. I got 5 Cory's. The type of fish is 5 blue spotted Cory's. I would take a pic but it's blurry. Yes, the fish are in a 20 gallon, I have 5 blue spotted cory's, 3 red eyed Tetra''s, 8 glow fish.

Blue spotted cories isn't a species name, so it doesn't really help me identify the species I'm afraid. There are a lot of common names that get used and misused for different fish, so I really need to see them to know what species.

That's important because cories aren't all the same in the requirements they have. If what you think are blue spotted cories are actually something like peppered cories (Corydoras paleatus) then they need cooler water temps than many of the tropical fish we keep, so we'd need to know the temp of your tank, and cross reference temp requirements of your other fish.

This is why it's best to wait before buying new fish and adding them, and to research the species and their care requirements before you buy them and bring them home.

So the next important questions are? Do you plan to get more red eye tetra to give them a bigger school? Or plan to buy any other different fish for the tank?

Will still need photos or video of the cories to be sure of species before knowing their requirements.

 

[10 Tanks]

For the cory's how do I know if my gravel is sharp? I picked it up and rubbed against my hand and it did not scratch my hand. So does this mean my gravel is not sharp. The gravel is fine and slips past my fingers while holding the gravel.
I just want to make sure everything is ok for my Cory's. They are quite active and swim in a school. I love Cory's as much as Betta's. Cool fish to watch and enjoy. I was thinking of using sand instead to be on the safe side. What fun that is going to be, to empty out my entire tank, and getting rid of all the gravel. I know it's all my fault I should of done my research, before buying the fish. Is there an easy way to get rid of the gravel? Is very fine and thin gravel.

Hello. The bag of gravel should have the word "polished" somewhere. I wouldn't worry about it. If you've examined the gravel and not noticed sharp or abrasive pieces, your fish should be fine. The barbells if injured in some way can heal in time. Just keep the water extremely clean with large, weekly water changes and feed a little variety every day.

10 Tanks (now 11)

 

[Aiken Drum]

Blue spotted cories isn't a species name,

Corydororas melanistius

 

[AdoraBelle Dearheart]

Corydororas melanistius

Ah, ty!

 

[Ichthys]

If you got hold of a wide enough length of tubing you could siphon out some of the gravel while doing a water change? That’s what I do… but I tend to keep big tanks so I can do it easily without removing too much water. I actually enjoy changing substrate, as all the fish gather round to supervise.
Also with big fish there are so many bacteria in the filters that the proportion in the substrate is negligible, so there’s no danger of removing too many, and you can do it all in one go. It’s very different with small fish.

 

[Alice B]

my bronze cories have done fine since I removed all small gravel from the undergravel side of their tank - they were getting it in their gills - and put soft sand on the other end of the tank. Even the one I was worried about that I saw trying to get a gravel bit out of his gill, has done ok and healed. Larger round gravel may not be preferred but it is tolerated and sand doesn't work on under gravel filtration so I have the compromise tank. Actually did my 40 long the same way, to allow future stocking. Pic right after the changeover. I'll get a current one today

 

[pettygil]

I wouldn’t empty the tank and remove all the gravel in one go, as doing so could mean removing the beneficial bacteria from the tank (assuming your tank has now cycled).

I’d remove about 50% of the water and scoop out gravel from half the tank, replace it with sand. I’d leave the remaining gravel in the tank for around 3 to 4 weeks to give the beneficial bacteria time to colonise the new sand. Then remove and replace the rest of the gravel. I wouldn’t worry about some gravel remaining in the tank.

The sand should be thoroughly washed or you’d end up with cloudy water.

Thank you, for your help.

Blue spotted cories isn't a species name, so it doesn't really help me identify the species I'm afraid. There are a lot of common names that get used and misused for different fish, so I really need to see them to know what species.

That's important because cories aren't all the same in the requirements they have. If what you think are blue spotted cories are actually something like peppered cories (Corydoras paleatus) then they need cooler water temps than many of the tropical fish we keep, so we'd need to know the temp of your tank, and cross reference temp requirements of your other fish.

This is why it's best to wait before buying new fish and adding them, and to research the species and their care requirements before you buy them and bring them home.

So the next important questions are? Do you plan to get more red eye tetra to give them a bigger school? Or plan to buy any other different fish for the tank?

Will still need photos or video of the cories to be sure of species before knowing their requirements.

My temp is around 80 degrees. I do plan on buying 3 more red eyed tetra's after my tanks cycle for a few weeks. I would try to take a photo, or video but every time I come toward the tank my cory's swim off. It's hard to take a photo of them. Here is a video of my Cory's. It's hard to get them on video, as they are quite active.

 

[Alice B]

they are really cute and fast but I don't know their species