I have a 40-50 gallon tank in my classroom that I inherited this year. When I started, I had a large pelco and 2 smaller plecos. I also had 9 larger goldfish (about 4") and one small brown eel. All but one goldfish died. I bought 18 smaller feeder goldfish from the local pet store. About a week later a few of them had ich and I lost several. I did a 50% water change and treated the water with IchGuard 2 (did this twice). I think the ich has cleared up. However, I'm still losing fish-about 1 every 2 days. I did just add a bubble wand to the tank yesterday. Now, in addition to my previous goldfish, I have 5 remaining small goldfish. My large goldfish seems fine, just the smaller ones seem to get weaker, then they hang out on the bottom of the tank for a day or two, and then my students see one floating. I tested my water yesterday and my pH is 7.8, the water is on the hard side, and my nitrate level is really high. I'm also seeing a lot of green/brown alge on the ornaments and glass of the tank. Please help!
Help! My classroom goldfish keep dying
- Thread starter kroann
- Start date
The important things to test your water for are ammonia and nitrite. They need to be zero and you would have to do water changes to get them to zero. Nine large goldfish are really overstocking a 40 - 50 gallon tank - could you measure the dimensions to find out exactly what you have and also what is the temperature of the water. Are you using any filtration?
(One goldfish needs at least 20 gallons and each additional another 10)
(One goldfish needs at least 20 gallons and each additional another 10)
Yep, measuring your water parameters are a must.
It's said that a single Comet (feeder) goldfish will outgrow a 55gal tank. Are you running a heater in the tank? Goldies are cold water fish.
I hear you on bringing ich into the tank. I once tried setting up a tank per fish store recommendations by 'throwing in some feeder goldfish' first. They brought ich into the tank. The poor buggers are normally diseased from the get-go.
It's said that a single Comet (feeder) goldfish will outgrow a 55gal tank. Are you running a heater in the tank? Goldies are cold water fish.
I hear you on bringing ich into the tank. I once tried setting up a tank per fish store recommendations by 'throwing in some feeder goldfish' first. They brought ich into the tank. The poor buggers are normally diseased from the get-go.
the ph of the tank is fine, a cycled balanced tank will have about 20ppm or less nitrates. nitrates are a sign that beneficial bacteria are doing thier job. BUT with adding that many gold fish they may be producing to much ammonia for the bacteria to handle and you may be getting an ammonia spike which will then also create a nitrite spike. so those are the perameters you really need to concentrate on. only things to drop the ammonia or nitrites is to either remove excess fish so the bacteria can handle the load, or do water changes untill the bacteria can handle the bio load. with gold fish i recomend removing them.
As for the high nitrates, plants that float will help with that. hornwort, java moss or other varients. with those plants they will suck the nitrates out of the water column reducing the food the algae can consume killing it off. also if you float something like hornwort it will reduce the light getting to the algae helping to kill it as well. for me algae is a balance issue. in a perfectly balanced tank algae wont grow. but show me someone with a perfectly balanced tank and i will show you a unicorn lol. I hope some of this information helps
As for the high nitrates, plants that float will help with that. hornwort, java moss or other varients. with those plants they will suck the nitrates out of the water column reducing the food the algae can consume killing it off. also if you float something like hornwort it will reduce the light getting to the algae helping to kill it as well. for me algae is a balance issue. in a perfectly balanced tank algae wont grow. but show me someone with a perfectly balanced tank and i will show you a unicorn lol. I hope some of this information helps
It is important when stocking a tank, giving medications, etc., to know the volume of water. 1 gallon = 231 cubic inches.
First of all, 'feeder goldfish' are typically not healthy. Also, the type of goldfish determines the amount of water they will require. A 'common' goldfish or the 'koi' varieties are suitable only for ponds. The 'fancy' goldfish need 20 gallons for the first, and 10 additional gallons for each additional goldfish as mentioned by others. The volume of your tank (40-50 gallons estimated currently) would mean you can only house 3-4 'fancy' goldfish without running into health problems.
Goldfish are very large waste producers and need large weekly water changes to keep up with their waste. Most that keep them do 50% water changes a week at a minimum once the Nitrogen Cycle is completed. More water changes are necessary until the parameters are stable.
The fish are likely dying of ammonia and/or nitrite poisoning. Massive water changes and using a dechlorinator that binds ammonia is the only way to handle this short-term. Reducing the number of fish is the only way to keep things healthy long-term.
You need to test for ammonia, nitrite and nitrate. The pH reading is not critical, nor is the measurement of hardness. What is 'really high' for nitrates? You need to be able to measure the actual amount of ammonia, nitrite and nitrate in ppm. Anything over 0 in ammonia or nitrite means you need to do water changes (making sure to match the temperature) immediately to bring the level down to zero. Any time you see a reading over 20ppm in nitrate, its time again for a water change.
Algea is caused by an imbalance in your water chemistry. Getting too much light (artifical or sunlight) will cause an outbreak of algae. Too much DOC (Dissolved Organic Compounds) - ammonia, nitrite, or nitrate - will also cause algae outbreaks.
First of all, 'feeder goldfish' are typically not healthy. Also, the type of goldfish determines the amount of water they will require. A 'common' goldfish or the 'koi' varieties are suitable only for ponds. The 'fancy' goldfish need 20 gallons for the first, and 10 additional gallons for each additional goldfish as mentioned by others. The volume of your tank (40-50 gallons estimated currently) would mean you can only house 3-4 'fancy' goldfish without running into health problems.
Goldfish are very large waste producers and need large weekly water changes to keep up with their waste. Most that keep them do 50% water changes a week at a minimum once the Nitrogen Cycle is completed. More water changes are necessary until the parameters are stable.
The fish are likely dying of ammonia and/or nitrite poisoning. Massive water changes and using a dechlorinator that binds ammonia is the only way to handle this short-term. Reducing the number of fish is the only way to keep things healthy long-term.
You need to test for ammonia, nitrite and nitrate. The pH reading is not critical, nor is the measurement of hardness. What is 'really high' for nitrates? You need to be able to measure the actual amount of ammonia, nitrite and nitrate in ppm. Anything over 0 in ammonia or nitrite means you need to do water changes (making sure to match the temperature) immediately to bring the level down to zero. Any time you see a reading over 20ppm in nitrate, its time again for a water change.
Algea is caused by an imbalance in your water chemistry. Getting too much light (artifical or sunlight) will cause an outbreak of algae. Too much DOC (Dissolved Organic Compounds) - ammonia, nitrite, or nitrate - will also cause algae outbreaks.
Thanks for all your help! I bought an ammonia testing kit after school and some ammonia reducing stuff that I'll put in tomorrow. This morning when I tested my water, the nitrate level was 200, so I did a 50% water change. I also gave the kiddos another lesson on how to feed the fish. Until recently, I haven't been doing water changes. I figured that because I had to add several gallons of water every couple weeks to keep the tank full (amazing how much water evaporates over the winter) that I didn't need to change out as much. I guess I should have done more research!
well the thing about water changes is that when water evaporates it's just the water. all the other compounds remain. so just topping off the tank is just mildly deluting the compounds. you need to remove the water fouling compounds which is done with water changes. We were all there before and i know u will get everything sorted out 
One thing I would add, goldfish are cold hardy, they also can tolerate salt reasonably well. If your Ammonia levels are high, then your Nitrites are probably going to be high, as well as your Nitrates. API master teskit is really worth the $20 it costs, in a class depending on the age of your students it can be an interesting introduction into chemistry as well.
Apart from what everyone else has stated, you might consider adding 0.3-0.4 oz of aquarium salt, or sea salt ( cannot contain yellow prusa soda ) to the tank, the goldfish will handle it, if your Nitrites are high it will help your fish to absorb Oxygen. Nitrite poisoning renders the hemoglobin in the blood unable to carry Oxygen, and your fish may suffocate even with a bubble wand, salt specifically chlorine in the salt decreases the methemoglobin ( which increases due to nitrites ) allowing your fish to breath again.
If Ich are still in the tank, the added salt will also do 2 other things, Ich in the tank ( if any still exist ) will find it harder to survive, as well as the salt activates an immune response on the fish to produce a slightly thicker slimecoat, which will also help prevent ich if it is re-introduced into the tank in the future.
Salt will not remove nitrites, it will give a false reading in api's master test kit until it's below 0.1 oz / gal but if your fish are suffering from nitrite poisoning (gills are brown or tan vs pink \ white ) it will increase the chances of them surviving.
Hope that helps.
Apart from what everyone else has stated, you might consider adding 0.3-0.4 oz of aquarium salt, or sea salt ( cannot contain yellow prusa soda ) to the tank, the goldfish will handle it, if your Nitrites are high it will help your fish to absorb Oxygen. Nitrite poisoning renders the hemoglobin in the blood unable to carry Oxygen, and your fish may suffocate even with a bubble wand, salt specifically chlorine in the salt decreases the methemoglobin ( which increases due to nitrites ) allowing your fish to breath again.
If Ich are still in the tank, the added salt will also do 2 other things, Ich in the tank ( if any still exist ) will find it harder to survive, as well as the salt activates an immune response on the fish to produce a slightly thicker slimecoat, which will also help prevent ich if it is re-introduced into the tank in the future.
Salt will not remove nitrites, it will give a false reading in api's master test kit until it's below 0.1 oz / gal but if your fish are suffering from nitrite poisoning (gills are brown or tan vs pink \ white ) it will increase the chances of them surviving.
Hope that helps.