Cloudy Water Solutions - Have Any?

My niece recently set up a 5 gallon fish tank with some mollies, and a sucker fish. The water was clear when she set up the tank with filter and aerator. Within a day, the water became cloudy but there was no smell. She is not overfeeding, and the fish appeared healthy. She has changed up the water, moved them into a 10 gallon tank and now a day later the water is very cloudy again. It almost looks filmy. The sucker fish died, so she plans to replace him, but I would think a day without the fish would not be a problem. She's thoroughly cleansed the rocks, filter components, aerator hoses, and the few rocks and castle that are in the tank. There are about 6 mollies and they did have around 8 babies which are in a small flotation tank to keep them apart. The pet store suggested some clarifier which she added yesterday, but after 24 hours the water is just cloudy and some of the fish seem to be struggling. Any tips or suggestions would be welcome. We've had fish before and never had this problem. We're starting to think maybe the fish are unhealthy or have some sort of condition we are unfamiliar with. Your help is greatly appreciated.

Hi MichiganMom,


Your niece had made several beginner mistakes. The problem was caused by several reasons.

1. I'd like to know what exactly species that "sucker fish" is. There are plenty of different species with a "sucking" mouth. Many of them are simply way too big to be in a 5 gallon tank. Without knowing the exactly species, it is hard to know for sure.

2. How many mollies were there? The exactly number is important.

3. It is an extension of the first two points. I believe the 5 gallon tank is simply overstocked with too many fish and unsuitable fish. When you have too many fish or too big of a fish (or both) in a too small of a fish tank, there will be problems such as ammonia poisoning. To make it short, ammonia is a toxic. All fish species produce ammonia on a constant basis through their gills, and the breaking down of their poop and leftover fish food. Basically they are poisoning themselves unless the aquarium has been "cycled" before the fish were added into the tank.

To understand it further, you need to read on our article of Aquarium Nitrogen Cycle and Fishless Cycling. It explains everything in details.
It is extremely important that all fish keepers must know.

However, not even aquarium nitrogen cycle will work unless the tank size and the filter GPH is suitable for the fish in there. Otherwise they are basically swimming in their own waste.
P.S. What filter is she using?


4. Was there a heater?
What was the water temperature? Mollies and many "sucker fish" are basically tropical fish. They can't survive for long in an aquarium without a heater to keep the water at at least 72F+.


5. It is wrong to wash everything in the tank.
All new filters require time to accumulate beneficial bacteria which will feed on the toxic ammonia. <--- You will know this once you have read the article of Aquarium Nitrogen Cycle and Fishless Cycling. Keep washing the filter will just make the aquarium nitrogen cycle start all over again.

6. It is also wrong to change all of the water at once. It is recommended to not change more than 50~70% of the water. Normally we change only 30~50% of the water once a week as a part of the regular aquarium maintenance. Too large of a water change will shock the fish with sudden change in water temperature, PH, hardness, etc. Any one of these factors can kill them quickly.



Please tell your niece not to add any more fish. If all her fish had died, it is time to do a fishless cycling before getting any new fish.

There were a lot of good suggestions in the previous post. But, whenever I set up a new tank, I put the water in after adding the gravel, decorations and any plants be they plastic or real,, then I let the tank run with no fish in for a week to let the water "settle down." That way, if there are going to be any cloudy issues, ect there are no fish in the tank to suffer plus it lets the chlorine filter/evaporate out. I know there are chlorine removers on the market that are very effective, but just letting the tank filter and sit with no fish in it is something I was told todo many years ago when I first started keeping fish.

(08-04-2014 12:08 AM)evelynmcgregor Wrote:  There were a lot of good suggestions in the previous post. But, whenever I set up a new tank, I put the water in after adding the gravel, decorations and any plants be they plastic or real,, then I let the tank run with no fish in for a week to let the water "settle down." That way, if there are going to be any cloudy issues, ect there are no fish in the tank to suffer plus it lets the chlorine filter/evaporate out. I know there are chlorine removers on the market that are very effective, but just letting the tank filter and sit with no fish in it is something I was told todo many years ago when I first started keeping fish.

I am sorry, your statement is wrong on several levels.
I have to correct it. Sorry.


First, while the chlorine in the tap water can be released into the atmosphere after a day or two by just letting the water sit there, the chloramine is much more stable and it isn't going anywhere. Commercial available aquarium water conditioners will remove chlorine and chloramine just fine almost instantly, and it is what almost all fish keepers use.


Second, letting an empty tank with no fish (no source of ammonia) to run by itself will do absolutely nothing to benefit the fish. Nope, it will not prevent cloudy water later on after you have added fish.
If you actually know why some aquarium get cloudy, and what Aquarium Nitrogen Cycle is, you would know it.

After adding the fish, the cloudy water is most likely caused by either bacteria boom (beneficial bacteria trying to multiply to feed on the ammonia produced by the fish) because the tank wasn't cycled, or there is too much organic waste in the water as a result of overstocking...or both. No amount of "sitting" with an empty tank will do any good to prevent this.

The only way to prevent cloudy water is to properly prepare the aquarium to receive the fish by using fishless cycling.

Fishless cycling is to use a source of ammonia to simulate the ammonia produced by fish to get the filter media to develop enough beneficial bacteria before adding the actual fish. The whole process may take more than a month to finish. The key is to have a constant source of ammonia. And the true goal of fishless cycling is to prevent ammonia and nitrite buildup after adding the fish. The true danger to the fish is the ammonia and nitrite which are both toxic while have no color and no smell. Only a properly cycled aquarium can prevent these two chemicals from building up.

Everything about fishless cycling is in the article of Aquarium Nitrogen Cycle and Fishless Cycling.

Cloudy water can be from several factors. Another poster has given you tons of great tips, I just thought I would add some things or give a different perspective! It could be a bacterial bloom, which happens at the beginning of cycling. I would suggest doing partial water changes frequently. Thorough cleaning and feeding less often also helps control bacterial blooms. Seachem Prime is a great product- it is the best and most concentrated water dechlorinator/conditioner if you are looking for one of those to help the tank!

(08-18-2014 05:41 AM)tess pfeif Wrote:  Cloudy water can be from several factors. Another poster has given you tons of great tips, I just thought I would add some things or give a different perspective! It could be a bacterial bloom, which happens at the beginning of cycling. I would suggest doing partial water changes frequently. Thorough cleaning and feeding less often also helps control bacterial blooms. Seachem Prime is a great product- it is the best and most concentrated water dechlorinator/conditioner if you are looking for one of those to help the tank!

SeaChem Prime is one of the water conditioners which will get rid of chlorine and chloramine from the tap water in order to make the tap water safe to use for the aquarium fish. A secondary function of SeaChem Prime which is unique, it can detoxify ammonia and temporarily turn it into relatively harmless ammonium.

It will not stop bacteria boom. Nor we want to stop bacteria boom. If a fish keeper never did fishless cycling before he added the fish, he will want the bacteria boom to get the (fish in) cycle done as quick as possible. You do not want to get rid of the good bacteria, you want them and you want more of them as soon as possible in a uncycled fish tank.

Partial water change will help lower the ammonia and nitrite buildup in an uncycled fish tank to relief some stress for the (dying) fish. Yes, most fish will die in an uncycled aquarium. Yes, the aquarium filter will try to cycle itself once the fish is in and the ammonia is building up, but most fish will not make it through the entire cycling process before getting killed by the toxic ammonia and nitrite. It is why we always recommend fishless cycling = cycle the aquarium before getting any fish at all.