Is my tank over crowded?

[pettygil]

Is my tank over crowded?
I have a 20 gallon high tank. Fish I have are:
7 glow in dark tetra's
6 red eyed Tetra
5 panda Cory's
6 blue spotted cory's
If it's over crowded. How many water changes should I do weekly? I'm not buyin any more fishes, unless my fish die, otherwise, I'm not adding anything more to the tank.
I'm keeping a close eye on Ammonia, and Nitrites, and Nitrates.

[Colin_T]

Do a 75% water change and gravel clean the substrate once a week. Make sure any new water is free of chlorine/ chloramine before it's added to the tank.

Clean the filter at least once a month. Wash filter media/ materials in a bucket of tank water and re-use the media. tip the bucket of dirty water on the lawn outside.

Monitor the fish for aggression. If they nip or attack each other, they are stressed and need more room. A 20 gallon long tank is better for fish than a 20g high because it has a bigger surface area (length x width).

[pettygil]

Is this a 20 gallon high, or long?
I think it's a 20 gallon high but I want to make sure.

[pettygil]

I got my red eyed Tetra's today and they are big. I also have 3 other red eyed Tetra's not as big. I must have baby red eyed tetra's. I have 6 red eyed Tetra's in my fish tank. I also have different sized panda cory fish. Some are big, while other's are smaller.

[pettygil]

One of my red eyed tetra's died.
My water is 0 ammonia
Nitrate 0.5
Nitrite 0
ph 7.4
So my water is ok, but one of the Tetra's went to heaven. I just got new fish today, could that be it? The new fish are doing ok, so far. It was one of the other red eyed that died, that I had for awhile. .
My temp is 77 degrees.

[Andy Sager]

Originally Posted by pettygil

Is this a 20 gallon high, or long?
I think it's a 20 gallon high but I want to make sure.

That appears to be a 20 high. Measurements for that is 24" l x 12" w x 16" H.

Your old Red Eyes have been through a lot so why one died could simply be from all it went through.
Unfortunately, when you buy schools at different times, you are bound to get fish of different sizes. That's not always a bad thing but sometimes the smaller fish take the brunt of any abuse. As for the Cory cats, males and females are markedly different in size so nothing to be concerned about there.
As for your tank being overcrowded, it's still new(ish) so even if you lose a fish or two, I wouldn't add any more fish for at least 6 months. This time will allow the tank to get really stable and your bacteria bed really established.

[pettygil]

Originally Posted by Andy Sager

That appears to be a 20 high. Measurements for that is 24" l x 12" w x 16" H.

Your old Red Eyes have been through a lot so why one died could simply be from all it went through.
Unfortunately, when you buy schools at different times, you are bound to get fish of different sizes. That's not always a bad thing but sometimes the smaller fish take the brunt of any abuse. As for the Cory cats, males and females are markedly different in size so nothing to be concerned about there.
As for your tank being overcrowded, it's still new(ish) so even if you lose a fish or two, I wouldn't add any more fish for at least 6 months. This time will allow the tank to get really stable and your bacteria bed really established.

I wont buy any more fish for awhile. So you said for 6 months to wait. I can do that. However, for the red eyed tetra, they need at least 6 and I only have 5 red eyed tetra's, is it ok to leave it that way. I only have 5 red eyed tetra's, since one of them died. Thanks for letting me know what sized tank I have. I was right, it was a 20 high.

[Andy Sager]

Originally Posted by pettygil

I wont buy any more fish for awhile. So you said for 6 months to wait. I can do that. However, for the red eyed tetra, they need at least 6 and I only have 5 red eyed tetra's, is it ok to leave it that way. I only have 5 red eyed tetra's, since one of them died. Thanks for letting me know what sized tank I have. I was right, it was a 20 high.

The numbers for schools are really more an arbitrary number so 5 is fine. The reason you don't want 1 or 2 in a school is because 1 alone could be stressed from being alone. With 2 there will be a leader and a follower and the chances of the follower being picked on by the leader is greater. When you keep fish schools, there is less chance of any one fish getting all the crap from the other fish. Psychologically, there is safety in numbers which is why fish school in the first place so you really want to keep schooling fish in schools, not pairs or singles.

Just an FYI, 20 longs are 30" L x 12" W x 12" H.
As for the timeframe, that too is not an absolute value. You just need to let the tank run with no problems for as long as you can handle it. In your case, you really shouldn't need to add too many more fish because your fish are still going to grow and as they do, they will take up more of the tank space which will limit the numbers of fish you can ultimately have in there. Truth be told, with Red Eyes and Glow Tetras and other fish already in there, if they were mature, you really shouldn't put any more fish in with them anyway. So if you wanted to add more fish, I'd say don't add but trade out fish for other fish. And if you wanted more fish by trading out fish, I'd change to fish that won't grow as large. A 20 gal is not really a large tank when it comes to how a fish sees it.

[JJenna]

Here's a nifty tool for you to get an idea if your tank is overstocked as well as seeing how changes in filtration will look for adding additional fish to the tank. You just put in your info, add fish and it will give you a percentage of how stocked your tank is. It's not perfect because the amount of hardscape, etc reduces the amount of available water in the tank.

https://aqadvisor.com/AqAdvisor.php?...engthUnit=inch

[pettygil]

Another red eyed Tetra died. I just did a 50 percent water change.
I just had two red tetra's died. I also added conditioner from Fritz.
I now have 4 Red Eyed Tetra's.
My water is fine. I checked it. I really did not have to do a water change but I did anyway.

[Andy Sager]

Originally Posted by pettygil

Another red eyed Tetra died. I just did a 50 percent water change.
I just had two red tetra's died. I also added conditioner from Fritz.
I now have 4 Red Eyed Tetra's.
My water is fine. I checked it. I really did not have to do a water change but I did anyway.

Are you losing the new ones or the old ones?

[pettygil]

Originally Posted by Andy Sager

Are you losing the new ones or the old ones?

The old ones. They were dead. I scoped them out with my hand. I only have one of the old ones left. The fish sent to me are still living. My water is fine, and did another water change. I can't figure out why the old tetra's died. They were not stressed, as far as I know. They just die.

[Andy Sager]

Originally Posted by pettygil

The old ones. They were dead. I scoped them out with my hand. I only have one of the old ones left. The fish sent to me are still living. My water is fine, and did another water change. I can't figure out why the old tetra's died. They were not stressed, as far as I know. They just die.

It could be that or the new ones, being larger, are harassing or intimidating them because they are smaller so they die. It's tough to say without an autopsy. If the water chemistry is good and none of the new fish are having problems, you have to add the fact that the old fish went through a cycling period where they were under real duress so their "natural" life spans will be shortened.
Welcome to fish keeping.

[pettygil]

Originally Posted by Andy Sager

It could be that or the new ones, being larger, are harassing or intimidating them because they are smaller so they die. It's tough to say without an autopsy. If the water chemistry is good and none of the new fish are having problems, you have to add the fact that the old fish went through a cycling period where they were under real duress so their "natural" life spans will be shortened.
Welcome to fish keeping.

Well on the good side my Betta's are doin ok, in separate 6.5 tanks.
It's my 20 gallon I'm have problems. I do check the water daily. My water is fine, now if I could just stop the other fish from dying. I wont add anymore fish I do not want too loose any more fish. I need to have an established tank. I understand now.

[Andy Sager]

Originally Posted by pettygil

Well on the good side my Betta's are doin ok, in separate 6.5 tanks.
It's my 20 gallon I'm have problems. I do check the water daily. My water is fine, now if I could just stop the other fish from dying. I wont add anymore fish I do not want too loose any more fish. I need to have an established tank. I understand now.

What you need to understand is that you CAN'T stop fish from dying. All you can do is create an environment that allows for and encourages them to live. The rest is up to them. I've seen a school of fish in a wholesale house die when someone put a net in the tank to catch some out. They panicked which gave them heart attacks. 20 fish all turning from brown to ghost white and quivering until they laid on the tank bottom dead. I've seen fish look at the top of the tank and without any warning, jump out of it. I've seen fish look up at the top of the tank then smashed into the cover on it and die. I've had a customer set up a tank specifically for a certain special order fish then when I finally got it in for him, lost it because he put something else in the tank in the meantime which killed the new fish. Except for this last example, you can't stop these things. You CAN make good water. You CAN put the right fish together in the tank. You CAN give them good foods to keep them healthy. You CAN buy your stock from reliable sources. You CAN prepare yourself for diseases the fish MIGHT get. You CAN join sites or clubs in your area to learn more about fish keeping. You CAN do a lot of reading about fish keeping. The rest, as I said, is up to the fish.