Sudden red gills on Cory catfish

[Byron]

How much play sand is needed? I might do it at some point but only if it doesn’t cause any problems and is easy to clean. Would it not get sucked up in a gravel vacuum or be washed away with water when cleaning it via cup?

The depth of the sand is important; you want enough for the natural colony of various bacteria to establish and live (the substrate is far more important that the filter for this), but not so deep that you have anaerobic problems beyond what is normal and necessary (in other words, not problematic). Plants that are rooted in the substrate obviously have a bearing on the depth. I tend to start out with roughly 1.5 inches (3-4 cm) of washed sand when spread evenly across the tank floor. Then I might push it a bit deeper in the back and shallower in the front, but I always have about 1 inch (2.5 cm) along the front as the minimum. Play sand comes in 25kg (50 lb) bags (at least in North America) and one bag will be enough for 3 or 4 10g tanks, so you will have spare but that is good, sometimes you might want to add a bit, or get another tank. It never goes bad.

As for cleaning, this really is not necessary if you are not overstocked or overfeeding. In some of my tanks I run the water changer above the sand, creating a sort of current that allows detritus to float up rapidly but not sand grains. Never dig down into the sand or it might all come up. In some tanks I rarely if ever do even this. I also have floating plants in all my tanks which makes a big difference as they suck up ammonia like a sponge.

 

[Skyelar Lattimore]

Okay, I will try doing as you say. What plants do you recommend? I had a Crypt last time and it died because I was told that I didn’t have to take it out of the basket. Obviously, that was wrong info. I also have iron supplement bottle that I can use though not sure how it works. I tend to have the Molly as the star of my tank, three Cory cats, four ghost shrimp, and a snail as they are my favorite tank mates. The shrimp tend to die after two months, though these last four that I had lasted three months, though from turning white which I’m not sure exactly how to prevent.

 

[Byron]

Okay, I will try doing as you say. What plants do you recommend? I had a Crypt last time and it died because I was told that I didn’t have to take it out of the basket. Obviously, that was wrong info. I also have iron supplement bottle that I can use though not sure how it works. I tend to have the Molly as the star of my tank, three Cory cats, four ghost shrimp, and a snail as they are my favorite tank mates. The shrimp tend to die after two months, though these last four that I had lasted three months, though from turning white which I’m not sure exactly how to prevent.

The shrimp death is due to soft water. Exoskeleton turning white is normal. Crypts are not easy plants at the best of times; they can melt at any change in their environment, from light, teemperature, nutrients, being moved (this is probably why you were told not to remove it).

Another point on the molly, this is a fish that if healthy will attain 3 inches (male) or close to 5 (some report 6) for females. It needs at least a 30g tank, and it has a high impact on the biological system. I'm only pointing this out so you know; the molly is not going to come anywhere close to this because of the soft water which is having such a negative impact on its system.

The easiest plants are floating plants, and being fast growers they also have the greatest benefit in terms of water quality, plus the shade which the fish appreciate. A comprehensive liquid fertilizer might benefit floating plants. Adding iron alone is very risky as this is a heavy metal and can kill fish, plants and bacteria should it be overdosed. Being a micro-nutrient, it is not needed in large quantity anyway, and alone I have had it kill floating plants. A comprehensive fertilizer like Seachem's Flourish Comprehensive Supplement for the Planted Aquarium is good. Seachem make several products under the "Flourish" name so make sure it is only this one. Brightwell Aquatics' FlorinMulti is much the same.

 

[Skyelar Lattimore]

I’m not going to get another Molly, I know that. So what am I supposed to do with the iron I have? I bought it and have barely used it. What tank mates do you recommend for soft water? The thing about floating plants is that it makes tanks look really dirty, and that would bother me. This is what I have:

 

[Byron]

I’m not going to get another Molly, I know that. So what am I supposed to do with the iron I have? I bought it and have barely used it. What tank mates do you recommend for soft water? The thing about floating plants is that it makes tanks look really dirty, and that would bother me. This is what I have:

Do not use that iron. I dumped mine in the back garden to get rid of it after I realized it was not beneficial. If you don't have all 17 nutrients the plants need, and all of these can occur from fish food (the fish excrement breaking down in the substrate) and water changes, thee plants will struggle and may even die.

Soft water fish--almost any fish from South America or SE Asia. Obviously many will be much too large for a 10g, so that narrows it down to "nano" type fish, like Ember Tetras, the dwarf rasboras in the genus Boraras, and so forth.

I don't understand your last sentence. Here are photos of 3 of my tanks, they all have floating plants and I would never have tropical fish without floating plants.

 

[seangee]

Here is a very real benefit of floating plants. This evening I discovered the tank in my signature had the filter turned off. This is entirely my fault as I forgot to turn it back on after last Saturday's water change because I was in a hurry and on my way out. I never noticed because the air pump was still running - this is connected to air stones and not a filter. So that is around 10 hours short of a full week with no filter.

The tank is fully stocked and I do watch my fish every day and had not noticed any unusual behaviour. But when I realised what I had done I immediately tested for ammonia and nitrite. Both had readings of 0.

I am certainly not suggesting anyone tries to replicate this as an experiment, but with around 100 fish in the tank that would have been a costly and traumatic mistake without all those plants.

 

[Skyelar Lattimore]

Why do pet stores suck lol. How do I get the sand in there? And should I keep some of the gravel on like one side or something to keep bacteria in there or can I just clean the whole tank and keep my filter pads the same? So the plants help the cycle to where the filter isn’t doing all the work? I also have a sponge filter that has been super loud lately so I’ve been keeping it off when I’m home. Can I just get rid of that? What plants work that are cheap? I really don’t have much more to spend on these fish.

 

[Skyelar Lattimore]

Is this okay? It’s cheaper than play sand as I don’t want more than one tank’s worth of sand. I don’t plan on having other tanks.

 

[seangee]

Yes that is perfectly fine. Rinse it well with fresh water in a bucket. Remove all the gravel from your tank - Its ok to do this over a few days. Then remove all your ornaments and 50% of the water. With the filter turned off gently pour the sand into the tank using a 2 litre soda bottle with the bottom cut off. Put the lid on and fill it with sand from the bottom. Then put it into the tank and when the lid is near the bottom take off the lid, allowing the sand to pour out without making (too much of) a mess. Repeat until you have enough sand in. Fill the tank and leave for an hour or so to allow the dust to settle before turning the filter back on. You can replace your ornaments and re-plant your plants. No need to remove fish. If you want to save your plants they will be ok left floating or weighted down while you are removing the gravel.

That is exactly how I replaced my buff coloured sand with black sand a few months ago.
Edit: You may want to do a water change every day while you are removing the gravel if it is mucky.

 

[Byron]

Is this okay? It’s cheaper than play sand as I don’t want more than one tank’s worth of sand. I don’t plan on having other tanks.View attachment 96341

T

Why do pet stores suck lol. How do I get the sand in there? And should I keep some of the gravel on like one side or something to keep bacteria in there or can I just clean the whole tank and keep my filter pads the same? So the plants help the cycle to where the filter isn’t doing all the work? I also have a sponge filter that has been super loud lately so I’ve been keeping it off when I’m home. Can I just get rid of that? What plants work that are cheap? I really don’t have much more to spend on these fish.

You want to go with just one substrate material. As soon as you have two different materials, it looks odd and it makes the tank seem smaller. And this is only a 10g tank, and given the problems, I would tear the tank down completely rather than trying to pull out the old substrate (who knows what you might dig up, given your history of deaths) with fish present.

I don't know where you looked at play sand, but it is less than half the cost of the linked sand.

 

[Kritastrophe]

Ace, Lowe’s, and Home Depot usually have play sand for 4$ per bag near me. If you have one locally to you I’d check their first and save some money.

 

[Guppy10]

Hi, just as an aside, I'm not sure what kills your fish but I will say that there is no right or wrong as well if it works then it's fine. There must be something fundamentally wrong for the losses. My Corys live on gravel same as years ago and are bullit proof and happy, may not be ideal but it's not a killer I assure you. Whatever works and all are entitled to an opinion but it's not black n white.
I'm " very overstocked with a bad mix of fish" but they do great and have just added 4 Molly's! No one asked about filtration which suprised me. I think your water is the problem.

 

[Byron]

The idea that Corydoras can be "happy" over gravel is a myth. There is a big difference between surviving and thriving, and as responsible aquarists we should always be concerned over providing what the fish we select require because this is the only way to ensure they will be "happy." And that means healthy.

Earlier this week this same topic of corydoras substrate was raised on CorydorasWorld, and this is Ian Fuller's response. And Ian knows more about this family of fish than everyone on TFF put together.

The first thing to remember with this group of fishes is that they are primarily filter feeders. They do not have cutting or crushing teeth like some of the predatory Catfish, nor do they have rasping teeth like the grazing Loricariid Catfish, these fish will sift the substrate, which in the majority of cases is sand.​

​

Smooth sand which been created over millions of years by the constant tumbling action of moving water, whether it be the oceans tidal and wave actions or the constant varying flow of rivers. The more the flow and tumbling action the finer the sand becomes.​

​

In some areas the sand found can be fairly course, and grains could be as large as one millimetre, or as fine as caster sugar, the one thing that will be common is that the grains will be smooth and not sharp and gritty like quarried sand as use in the building industry.​

Over many years I have spent many hours watching, and filming Cory’s feeding, in some cases it is quite comical, especially with the larger straight (Lineage 8) and curved (Lineage 1) snouted species who tend to bury the deepest, Some almost completely burying themselves when they dive right in searching out the food they sense is there. I have taken video clips of the feeding actions of several species from different lineages. And all, even the smallest species will mouth the sand.​

Many people argue and state that “Their Cory’s are perfectly happy living over gravel”. But I find it very difficult to see how they can determine the happiness of a fish. They may be surviving and because they are actively scurrying around in their constant hunt for food are seen as being happy.​

​

The biggest problem with using any type of gravel in an aquarium is that food particles will fall between the particles and decompose, and if the aquarium is not maintained and or filtered adequately the water quality will deteriorate very quickly. The other danger as far as keeping Cory’s over gravel is the fact that they cannot easily move gravel to access the particles of food within it, and if the gravel is of anything other than smooth and rounded particles they can and often do damage their delicate barbels and mouths parts.​

​

As I hinted at earlier, different forms and sizes of Cory will feed at different levels in the substrate, from dwarf species working the surface, medium round snouted species delving five or six millimetres into it, and the larger straight and saddle snouted species often burying themselves​