I bought this tank 2 weeks ago, fish included, two 8" albino's. the person I bought it from raised the fish in this tank from 2'' till now. they said they were just tired of keeping fish. the tank was in a back bedroom and was not being maintained well. I took a sample of the water to the pet store and had it analized, they said the ph was kinda high, nitrates were very high,amonia was a little high, and metals were high. I saved half of the original water and used it to set up the tank, when I got the results about the water tests, I figured the best action was a regular partial change, how often and how much? thanks in advance for any advice

How big is the tank and fish? I'm guessing the answer is going to be quite a small tank going by the fact that you saved half the water.

It really does depend on the size of your tank to how often, and how large the water change should be. Once your tank and cycled you need to keep an eye on the nitrate level. If the tank is cycled properly, you shouldn't have to worry about the ammonia or nitrite. You should be aiming to keep your nitrate levels below 40 ppm. The smell of a tank you have, the quicker the nitrate levels are going to rise. Now it all depends on how big this new tank is. Remember that two Oscars do require over 100 gallons of water. Once you start housing Oscars in small tanks, you are going to find that your water quality diminishes quickly. For this reason, you might find it necessary to do more than one water change a week. So I can't really give you an exact figure. You'll just have to you monitor your water conditions to see what kind of work you are going to have to carry out on it.

My motto is, if you don't like tank maintenance, either get a very large tank, or don't keep Oscars

I allready know my tank's way small. It's a 38. They've been raised in it from what I'm told. I'm willing to do whatever I need to to keep them healthy untill I can get a bigger tank. Thanks for the input, I want to keep the fish if possible.

You need to keep ammonia and nitrite to zero. With a cycled tank with the correct filtration this should be easy. Your filtration should be rated for twice the size of the tank when keeping oscars(if you need to get more filtration get one that will do the bigger tank you are planning-you cant over filter).

As for the nitrate you should ideally keep this below 20 but below 40 is acceptable. To reduce nitrate you do water changes. Test the water weekly and if the nitrate gets too high then either change the water more often or do bigger changes. If you find the water changes are too muc or too often for you then get either get a bigger tank or get rid of some fish. I change 50% once a week.

Thanks for the info, I'm doing a 10 gal water change every other day. I'm using 'topfin tap water dechlorinator' in the dose recomended, also a little 'aquarium pharmaceuticals' "stress coat", with each change. I have frozen blood worms for them but I'm not feeding that untill I get the water right. they're on pellets right now, still eating well. I've got fresh cartridges in the filter, and will be changing the carbon in them every week. The filter is a 'Secondnature Whisper Power Filter...#3' is this enough filter for a 38 gal? Any and all recomendations are welcom. I'm new to oscars. They needed a home, trying to give them a good one.

I dont know the filter you are using so hopefully someone who does will chip in. Alternatively look on the web to find out what tank size it is rated for

I think carbon needs to be replaced every 6 weeks or so but i personally wouldnt bother. Loads of people keep oscars and dont use carbon. It is argued that it might be a cause of hole in the head (HITH). Also you will save on cost. Replace it with some biological media (the rocks in the filter). If you dont have a basket to put the rocks in and it needs to be in a bag use the foot end of a pair tights to put the media in and knot it up

They don't sell these type filters in the United Kingdom which is why we aren't really familiar with them. They seem extremely popular in the United States though. Check the website out below, it will give you information on the various models. You can tell us which one you are using

www.petco.com/product/6315/Tetra-or-Seco...d-Power-Filters.aspx

In one of my tanks I had 2x hob filters rated for 210 gallons and a 70 gallon tank and it was amazing how much waste was left in the bottom of the tank with 3 baby oscars I switched over to cannister that I can change the media about a week or so ago and I will never go back but thats just my opinion.