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Freshwater Fish and Aquarium Questions

Freshwater Aquarium Setup Questions from: Freshwater Aquarium Setup
From: Mathew Schultz - Aquarium Lighting
Hello, I am a brand new fish tank owner, I bought the fish tank for my 2 year old daughter as a christmas gift. Your website has been a great help to me. I do, however, have a question I need an answer to that I can't find on your website. Does the tank light need to be turned on 24 hours per day, or do I turn it off at night? Thank you for your time, and once again, your website has been a great help to me.
Thanks for the compliment on the site and welcome to fish keeping! Fish need to rest just like us and will appreciate some down time with the lights off. A good range of time to keep the lights on for a fish-only setup would be 6 to 10 hours per day. More information on fish tank light.

From: Greg - Algae Problem
I have a 72 gallon bowfront, I had a 30 gallon long that I moved the gravel, water and fish. The tank was perfect for about 3 weeks, 2 water changes. Now its a sort of hazy greenish color. I suspect an algae bloom because of the long light hours, but wanted to make sure without going the chemical route. I've read that too many chemicals is just as bad as none, purists preferring only to dechloronate. Please advise. The fish seem very hungry and happy so they don't seem stressed and no smell.
Try to cut down on the amount of nutrients in the tank by cutting back on the amount of food that enters the tank, removing some fish if overstocked, and/or changing foods if the foods you're using are high in phosphates. Keep up with the partial water changes on a regular basis (weekly) during Aquarium Maintenance and shorten the photo period to about 8 hours per day and see if the situation clears up. Try this route before taking the chemical route. Using more chemicals than necessary is only treating the symptoms (green water) and not the root cause (high nutrient levels) and you would have to continually do this to keep your tank looking nice. Please try the non-chemical route first.

From: James S. - Overstocked Tank?
My name is James and I am somewhat of a beginner at owning an aquarium. I have been around them from time to time but have never officially owned one, so even my basic knowledge is not broad. I have a 55 gallon tank with 2 Oscar's, 2 Bala sharks, 1 Pleco, an Iridescent shark and I believe a black tetra (the cat fish and the tetra came with the tank). I want to first make sure that my feeding is done correctly as well as tank care. I have been feeding twice a day with one Oscar on goldfish and the other on pellets, unless he feels like a fish and there is one small enough for him, the rest get flakes and I drop two shrimp pellets for the Iridescent. I feed the second time with pellets for both the Oscars and bloodworm's for all (the Oscars will partake as well) and more shrimp pellets for the Iridescent and an algae wafer for the Pleco. Is this a good plan or should I change it up somewhere? It seems to be going well but i don't know how much of the flakes are getting eaten before they dissolve, they devour the worms though. I think the Pleco is also eating some of the shrimp and the Iridescent goes after the wafer a little too.

I have only owned this tank for two weeks and have done one cleaning. I have read a lot of info from your site and have come up with this so far. My cleaning schedule is 20 percent every two weeks with a filter rinsing. My main filter is a canister with 4 levels of media, I change the white fine filter media (I believe it to be filter floss, it came with the purchase and I haven't had to buy more yet) every change. I am looking at changing the carbon every other water change, but I don't know when I should change the ceramic. My instruction say to only change one part at a time but I wanted to get some more advice before my next cleaning. I also believe that the last owner did not change the water all that often, he left some in when I bought it to keep the bacteria alive. When I changed the fine media it was pretty dark and when I was gravel cleaning there seemed to be a lot of debris and crud. My water is still somewhat cloudy and I have started running a second back mounted canister filter for a duration to try to clear it up. I have been testing the water every week and there are no abnormal readings, the water does seem to be a little hard but some I have found that comes with living here.

Should I clean more often? There doesn't seem to be any immediate problems and I just wanted to see if you all had some advice and what I could do about the cloudiness? Thank you for your time and you have a very informative and excellent website.
Hi James. While it may not seem like it now, the adult size of the fish you currently have makes your tank way over stocked. These fish will not lead good lives and will be living in increasingly bad water conditions as they grow larger. Here are some links to read up on these species:

Common Pleco can grow to be 12 to 18 inches as adults
Iridescent Shark can get up to 47 inches
Oscar Fish can get up to 12 inches
Bala Shark can get up to 13 inches
Black Skirt Tetra Is this your tetra? It stays quite small and won't last long in your tank.

You need to take back the iridescent shark, the tetra and the bala sharks. You could potentially keep two oscars in a 55 gallon tank but you'll need to keep a rigorous maintenance routine in the form of frequent large water changes. The iridescent gets way to big for most home aquariums and the bala sharks like to have alot of swimming room and may not do that great with oscars. It sounds like you have some pretty good filtration and it should be fine for 2 oscars, but you will need to stay on top of the water changes.

The cloudy aquarium water could be from the amount of food entering the tank, the fish waste and a bacteria bloom which is usually the sign that the Aquarium Nitrogen Cycle is starting. You'll need to get a good Master Aquarium Test Kit that tests for ph, ammonia, nitrite and nitrates (at minimum) and monitor your water frequently during the cycling process.

As far as filter maintenance goes, it wouldn't be a bad idea to change the white filter floss or at least rinse it well in discarded tank water every week or every two weeks. You should never need to replace the ceramic rings since they are the place where the good bacteria grow and this bacteria is what helps keep the ammonia and nitrites in check. You'll be removing the nitrates via the frequent water changes. The carbon could be replaced once a month or so.

So, our advice would be to take back the iridescent shark, the tetra and the bala sharks and get a refund or store credit. Keep the oscars since they are great fish with tons of personality with the stipulation that you will be staying on top of those water changes and filter maintenance.

From: Mark - New Tank Syndrome
I have bought a 3 and 1/2 foot tank with light and filters. Poured some tap water and added some pebbles. Then went to an aquarium and bought some good looking fish (nearly 25 of them). Dropped them into the tank and saw that every day at least a few fish die. This tank water colour also changed to a gloomy grey colour. Then I have decided to surf the net and found that I have missed the aquarium nitrogen cycle and to remove the clorine.
Now what can I do to prevent further death and to ensure that my tank is healthy?
The first thing you should do is try to take back most of the fish that are still alive to the fish store and ask them to hold them for you while you cycle your tank. A good fish store should help you out here. Then get a master aquarium test kit which is usually cheaper than buying the test kits individually. If you still have some fish in your tank, test your water frequently (daily or a few times per week) and perform partial water changes as needed to lower the ammonia and nitrites in the water. Cycling with fish can take longer than doing it fishless for this very reason. You don't want your fish to die so you have to perform those water changes, but those water changes are prolonging the time required for your filter and tank to complete the cycle since you're removing most of the ammonia and nitrites via the water changes. Please read the nitrogen cycle page for ideas on how to speed up this process and for doing it fishless.

From: Lizzie - Upgrading to a bigger tank and Fish Transfer
Hello, I have bought a second hand tank which is bigger than my other tank. It is three foot wide and fifteen inches tall. I have, already established, a two and a half foot tank which contains a large pleco fish (about 12" long). I would like to know how to ensure that this new tank is disease free and how to transfer the pleco without harming him. I assume that I will move the water from the old tank to the new, but how much extra water can I add without diluting it too much. Someone said to clean the new tank with bleach and ensure it is rinsed well. Is this right? I really would appreciate your help as we are attached to this fish and would hate to harm him. Thank you.
Hi Lizzie - Glad to hear that you're getting a bigger tank for your Pleco. If we're talking about a common pleco, it's still on the small side if we calculated correctly (approximately 30 gallons)? Using bleach to clean the new tank is not really necessary. If this aquarium had fish in it before, simply rinse it out thoroughly and wipe down the inside walls with just water. Do not use soap or chemicals. You can use some of the old water if you like and it might help the cycle in a small way, but be sure to keep the old tank's filter media floss to use in the new tank's filter. Also put some of gravel from the smaller tank in some old pantyhose (for easy removal later) and place it in the new tank. These two items, the floss and gravel, from your old tank will help you get your aquarium cycle started in the new tank.

Once everything is up and running for a few weeks and the cycle has completed, slowly acclimate fish to your new tank.

From: Denisia - Dieing Fish
My boyfriend just bought me swordtails. This was about two and a half weeks ago and since then every single fish has died in my tank with the exception of my sucker fish and my catfish. They all started swimming backwards and upside down. What happened?
Wow. This is a totally open ended question that will be difficult to answer without much more information. When posting tank questions it is extremely helpful to post your water parameters along with the question. Include things such as the temperature, pH, ammonia, nitrite, nitrate, age of the aquarium, tank size, filter used, etc. The more details, the better.

Is this a new tank setup? If so, do you know about the aquarium nitrogen cycle? If it is an established tank, did you quarantine your swordtails before introducing them to your display tank? If not, they could have had a disease that could have been the reason for the tank wipe out. Are you using an undergravel filter and did you recently do a large water change? Aggressive gravel vaccuming can be harmful if harmful gas pockets that sometimes form under UGF plates are released into the tank. Any large infusion of new water with drastically different water parameters (pH, temp) can be equally harmful. Sorry for the lack of any answer but there are too many unknown variables here.

From: Lance - Goldfish with Tropical Fish?
I have a 30 gallon tank, my fish all do well in the tank. My daugthers have a goldfish in a 1.5 gallon tank. No matter how often we clean the tank the water turns orange. We want to move the goldfish the larger tank but we are afraid that he could have something that might harm the other fish, what could that be and do you think he'll be fine with the other fish?
Goldfish are heavy waste producers and need a larger and well filtered tank. preferably at least 10 gallons per goldfish and even more gallons per fish for larger goldfish. Mixing them in with tropical fish may not be a good idea since goldfish do better at slightly cooler temperatures than tropicals. It's good that you want to move your goldfish to a larger tank but it would be better to get it a larger tank of it's own that can be kept cooler (around 70°F).

From: Carter K. - Stocking Levels
I was wondering if this setup would work: 10-12 tiger barbs, 2 clown loaches and a red tailed shark. I was planning on keeping these fish in at least a 29 gallon tank (the 29 being a last resort) it will have some sort of cave along with some live floating plants (any recomendations?). There will be either very fine gravel or some sort of sand. I do not know the filter or heater type I will get yet. Do you think these fish would do okay in this setup?
A 29 gallon fish tank is too small for an adult Clown Loach. The clown loach can get up to 12 inches (30 cm). Please use the adult size of the fish you want to keep to determine the tank size you'll need. As far as compatibility goes among these species, this mix of fish should be able to be kept together in a much bigger tank. Glad to read that you're researching before buying though. Kudos to you.

From: Marcus - Cloudy Water in New Aquarium
I have just setup a new freshwater aquarium, and for the first 2 days it was very clear and clean, but now I have been adding a little bit of fish food every 12 hours and it has gotten a little cloudy. Is this usual and is there any way I can get rid of or stop this from happening?
Yes, this is normal and indicative of a bacterial bloom at the onset of the nitrogen cycle. More info here: cloudy aquarium water.

From: Jim Prochnow - Need way more information
My grandson has a 10-gallon tank with 4 danios, 2 swordtails, a 3 female guppies. We have had 3 male guppies die in succession within the first 1-2 weeks of being introduced to the tank. All the other fish remain healthy. I'm at a loss.
That was too many fish for a 10 gallon tank. You're most likely at your limit since the death of the 3 male guppies. We do need way more information before we could guess as to what the problem(s) is/are. We need info such as water parameter readings for ammonia, nitrite, nitrate, pH, temperature, etc. Has the tank cycled? How long has the tank been set up? Is their good surface agitation for gas exchange at the surface so that oxygen levels can remain at adequate levels? How often do you perform water changes? What type of aquarium filter are you using? How were these fish acclimated and what are you feeding them? Etc, etc.

From: Kelly - Purpose of Aquarium Filter
The purpose of the filter is to remove large particles from the water right? So does it have to run 24-7? Is there another purpose for the filter? Thanks for all your help. This forum has been a huge resource for myself and my kids.
The mechanical aquarium filter is designed to remove larger particles via the filter media (floss). You do need to leave it running 24/7 to keep the materials trapped in the filter floss from quickly rotting. If you did run it only periodically, you'd have to change out the filter materials after turning off the filter and then insert new materials before starting it again. The mechanical filter can also aid in gas exchange and you could also use activated carbon to remove dissolved organics from the water which will help keep the water looking and smelling clean. In fact, most replacement media for power filter for instance, have activated carbon inserted in the middle of the filter floss. Remember to change it (or at least rinse it with discarded tank water) periodically. Neglecting to do so will lead to nitrate problems down the road.

For our power filters, we like to buy the cheap Filter Fiber (filter floss) and make our own replacement filters. We replace our power filter floss frequently and use the cheap stuff. About the only time we don't is when we need to use activated carbon and then we sometimes use the regular filter sleeves, since they are better designed to hold in the carbon. But you can also buy the mesh bags for using activated carbon in your filter. Old pantyhose works too.

From: Becky - Stocking question
I've just bought a 10 gallon tank that I'm currently cycling. I just want to keep some neon tetras in a shoal. How many do you think I could keep in that size tank? This site has been invaluable to me for setting up my tank so thank you.
If that's all you're going to keep in the tank, a group of 5 to 7 should do fine. The neon tetra is a great fish, lots of activity and beautiful colors. They've been getting a bad rap lately for not being as hardy as they once were. Take your time when acclimating them to your aquarium. Try the slow drip method of acclimation with these fish to lessen the stress levels when introducing to your aquarium. Thanks for letting us know the website helped you. Always glad to hear that, thank you.

From: Kristine with a compliment
Thank-you, Thank-you. Your web site is the best. The information is very good and I've learned so much. This is my first freshwater/live plant aquarium and at first it scared the beans out of me. But I'm cool with it now. Thank-you
Excellent to hear, glad to be able to help. Thank you for the comment.

From: Jack Smith - Fish Compatibility
Hi - I love your website and I recommend it to all my mates. I was wondering if you can put a siamese fighting fish in with a few neon tetras if they werent too cramped.
If you have a filter, heater and big enough aquarium for housing these fish then you shouldn't have problems with this stocking scheme. The betta (siamese fighter) should stay towards the top of the tank whereas the neon tetra will stay in the middle to lower levels. For tetras, the neons are very peaceful but many people (even veteran fish keepers) are having problems keeping neons. They use to have a very hardy reputation but that seems not to be the case nowadays. Keep up with the water changes and keep the nitrate levels on the low side.

From: Gina - New Fish Tank Questions
Hi! We just bought a 48 gallon tank and were instructed by the store owner to wait 5 days with the power filter running before we bring in the fish. We had the water tested before we placed the fish in and we must say we are a bit confused with what to do now after reading all this information on this amazing site. If all the readings on the water were safe/normal do we still have to do regular testing? Did that mean that our cylce stage already passed?

Our tank is white cloudy, so should we do the 25 percent water removal and less food step next? Also, we have 3 tropical fish and one goldfish. The tropical fish have all picked corners and hideouts and rarely move. My concern is feeding. When we try to feed the tropical fish, the goldfish swims around and eats everything up before they get a chance to. Hes not aggressive but we end up overfeeding the goldfish because we keep trying to put food in for the other fish to have. They are all around the same size as well. Should we return him? Is there a trick for feeding greedy fish?

Next question is that one of our tropical fish is a dalmation fish and he has planted himself behind the heater in the corner. He does not move much and is pressed up against the heater. Is it bad for the fish to be that close? Is that normal behavior? Does is mean that he is cold? Thank you for your help!
Unless you're using something like bio-spira or an established filter, 5 days is too soon to consider a tank cycled. The white cloudy water is most likely indicative of a bacteria bloom. Please read or re-read about the "aquarium nitrogen cycle". To increase the chances that your current fish survive you'll need to perform frequent partial water changes throughout the cycle or better yet, try to get your hands on some bio-spira or filter media from an established tank. Once your tank is cycled and assuming you improve your water quality throughout the process the fish should go after the food. You definitely don't want to overfeed here as it will only make the water problems worse.

Goldfish can be very hardy and the water quality issues may not be affecting it like the tropical fish. Goldfish are heavy waste producers, different water requirements and I wouldn't mix the two. The dalmation fish sounds like a Molly? Depending on the temperature of the tank, it could be cold or just stressed and looking for someplace to hide.

Good luck with your aquarium. It sounds like you were given some questionable advice by the store owner. This does indeed make it harder for those just starting out and is bad business.

From: Taylor H. - Fish dropping like flies
I recently bought a 10 gallon tank for my daughters birthday, and being a first timer I bought the fish along with it, took it home filled it up, added some aquasafe and threw in the fish! It's now 3 days later and my fish (I bought 18!) are dropping (well floating) like flies! Needless to say my daughter is quite unhappy and I guess I can only hope a few survive the cycling now that I know why the fish are dying in my white cloudy tank. I guess in a few weeks I can replace a few fish. They should really tell you about this cycling at the store! Thanks so much for all the info, at least now I know what is going on.
A good store will mention the aquarium cycle, especially if they know you're new to the hobby and they wouldn't have let you purchase so many fish for a 10 gallon tank. We as hobbyists though need to be proactive in our research efforts beforehand as well. A fish tank can provide some good bonding and educational opportunities for you and your child. Good luck with your new tank and have fun learning about this great hobby.

From: Geoff - Too many fish in tank
I have recently purchased a red bellied pacu and I placed him in the tank and he swam very erratically and is currently hanging at the bottom. He bashes his head into the wall, is not eating and is an all around crazy fish. So I have quarantined him and would like to know what to do. In the tank he was in it was 2.5 feet long 2 feet tall and 1.5 feet wide. I know it is too small for him and I would love to buy him a new tank but I am young and currently low on cash for now. All ph levels are normal, same with temperature and all the other good stuff. He is about 4 inches and his tank mates are a giant danio 3.5 inches, a tinfoil barb which is the same size, 3 penguin tetras and 2 rosy barbs that are 2 inches and 1 pleco about 3.5 inches. Please help!
You need to check more than just the pH and water temperature in your tank. You also need to check ammonia, nitrite and nitrates at a minimum. You have way to many fish for this aquarium. Some of these will get way too big for it, such as the Red Belly Pacu, the Tinfoil Barb and the Pleco. You'll need to return these fish for store credit, get a much larger tank or give them away in order for them to have a quality life. Please research the fish before buying them and read up on the freshwater articles in the beginner's section which is linked in the left navigation under Beginner's Guides.

From: Jodi - Cloudy Aquarium Water after water change
I have 50 gallon column freshwater tank that has been set up for 5 months. 2 balas, 4 clown loaches, 2 silver dollars, 2 dojo loaches and 4 zebras. I have a Fluval 450 also. How can I prevent the water from getting cloudy after a water change? It is crystal clear beforehand.
Hmmm, maybe you could use a filter on your faucet to filter the replacement water before adding it to your tank or even let the replacement water sit for a couple of hours to let the gases dissipate. It's worth a try and those faucet filters are really inexpensive. Just an FYI - your tank is overstocked and will lead to problems down the road, sooner rather than later. The Balas and clown loaches can get quite large.

From: Barb - Smelly Aquarium
Question - I have a 29 gallon tank which has been going for 2.5 years, the home of community fish. I have recently added 3 Rummy Nose and 3 tetras but the tank is not overcrowded. The water is clear, the tank is clean, but it has recently developed a very "fishy" odor. Any suggestions? Thanks.
Try using activated carbon in your aquarium filter. Or, if you are running activated carbon, replace it if it's been awhile. Activated Carbon should do the trick, along with regular partial water changes and gravel vacuuming.

More Freshwater Aquarium Setup Questions 2

Author : Mike FishLore

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