Questions on cleaning fish tanks

In all the years that I have been in the fish hobby, I have never encountered as many problems as I have had lately. I have 2 tanks, they are both about 110 gal. One has brown and green algae, and I have to keep scraping the algae off the glass. I have been doing water changes in both tanks every two wks. The fish in the tank with the algae are very healthy. The other tank is the one with the oscar that has the dropsy. No algae there,but there must be something wrong for me to have had problems with my jaguar cichlid, and now my poor oscar. I am going to run water samples in to see if there is a problem with the water in both tanks. How often should I be doing the water changes? I always use a python to vacume and change the water. How can I avoid stirring up dirt and harmful bacteria when vacuming? It seems like the water is still slightly cloudy afterwards, too. Thanks. Also, the oscar tank has a 350 magnum filter with undergravel filtration. It just seems like it's never clean enough!

 

Hi Nano, What I'm going to tell you, you probably won't like but I'm going to anyway. Get rid of the UG filter and you probably will get rid of your problems. I used to love UG's myself but the reality is that they build up some nasty bacteria under them that create all kinds of problems, and after about 6 months of buildup about the only way to get the tank back to normal with it in there is to break the tank down, clean and recycle. The reason the water is still cloudy after vacumming is because you are stirring up the waste (and bacteria) underneath the UG filter. If you think back I believe you will find most of your problems have occured shortly after vacumming your tank and stirring up what is underneath the UG filter.

 

Thanks for the info! I had a feeling about those undergravel filters!! I never liked them! My larger cichlids would always dig up the filter plates, so they were really useless anyway. you are 100 percent right, It would always be after I had cleaned the tank. My jaguar developed swim bladder problems, and the Oscar developed dropsy. I am sick about the Oscar. About how thick should the layer of gravel be? I usually keep large cichlids in there, and they are terrible diggers. I have about 1 - 1 1/2 inches of gravel on the floor of the tank. Thanks again!

 

The amount of gravel you have now is fine. After removeing the UG you should be able to vacuum out more of the waste than you have been able to in the past. With the UG filter gone most of the waste will collect in the top 1/4" of your gravel. This will make the Magnum filter a little more efficient and remove the cloudiness from the tank. It should also make your regular vacuuming and maintenance a little easier.

 

When I take out the undergravel filter plates, I will have to find another way to add oxygen to the tank. I was using powerheads with the undergravel filter, so was wondering what to do now. The power heads can't be used for anything, can they? Do I need to buy an air pump, and if so what size for a 110 gal. tank? And as far as air stones or air tubes?The tank is a 72 in. long tank. Thanks.

 

Just run airline with an airstone on the end. You can conceal the airstone behind a plant or rock or any other decoration. Any pump rated for that size tank should be OK. The difference in size on air pumps is due to the size of the diaphragm inside the pump. A pump rated for a smaller tank will have a smaller diaphragm. This is important in overcoming back-pressure. Airstones will need to be replaced periodically. When they start to become clogged there will be increasingly fewer but larger bubbles until it becomes clogged altogether. It's been a few years since I purchased an air pump but if there is a PetSmart near you, you might check there. They used to market their on air pump which carried a lifetime warranty. If anything went wrong with it they would replace it. Just hang on to the sales receipt and the box the pump comes in.

 

Dear Nano,
1) I change some water when I clean my external hang-on filter.
2) You do not have to avoid stirring up the dirt. The dirt is in the aquarium anyway. You can deploy some Malaysian Trumpet Snails and Asian Freshwater Clams. They eat dirt and aerate the gravels.
3) Undergravel filter is the first most effective bio-filter but I will rather choose the second most (hang-on filter) because of the cleaning difficulty of the first.
4) Put some aquatic plants in (you didn't say you have plants). They can really improve the water quality. Imagine in the city without plants you will feel stuffy.