I'm right in the middle of a rummage sale but I'll check the tank and get back with all the details asap -- but is there anything I can do for my fish? She is a fantail and in just the last couple of days has started floating at the top on an angle with her head more down. Not gasping or anything, just hanging there. I don't want here to die! What do I do?

Hi, Nicksma, and !
What is important for us are a few more details about your fish, the tank setup and so for. There is a big white box on top of this section - if you could answer as many questions as you possibly can, that gives us a better picture about your fish, and possible causes of his floating, which can have different causes, from overfeeding to high nitrate levels.

As a very first measurement, besides checking your tank for ammonia, nitrites, nitrates and pH, you can fast your fishie for 2-3 days, then continue feeding him with just cooked and deshelled peas, nothing else for a day or so. If the floating is food related, you should see an improvement after a couple of days...

Ammonia reads between ideal and safe
Nitrates are about 40 mg/L
Nitrites are 0
pH level is 7.6
Hardness is "very"
** the alkalinity (KH) turned the strip blue - the test only shows up to green so I'm assuming that that means the alkalinity is extreme!?
It's a 10 gal tank that we've had for a couple of years with a biofilter. There are two goldfish in it - that's it. The one we had some problems with tail rot, but he's been fine for a while. This fish has always seemed well until the last couple of days - now she floats to the top of the tank.
We feed Tetrafin every morning - only a small pinch.
A couple of days ago my husband changed out part of the water, which is done periodically - and added some salt to see if that would help.

Ok - Could it be the alkalinity? What should we do? Will she live?

I don't think it is the alkalinity of the water. Goldfish are very tolerant of that.

I would suggest two things. First, since you are overstocked with 2 goldfish in a 10 gallon tank (the generally accepted rule of thumb is 10 gallons per fish, so if you can move up to a 20 gallon tank in the future, that would be great), but for now, I would suggest doing more frequent water changes. I change about 30% per week in my tanks, but with a 10 gallon with 2 fish, I would change 50% per week. I would rinse out the filter material once per week also.

As Andrea mentioned, try fasting the fish for 48 hours. See if the fish still floats after the fast. Some fish float due to constipation and gas. If you find that the fish isn't floating when it isn't fed, then you probably have a fish with those kinds of issues. In that case, a more varied diet, and soaking food before it is fed, will help. With the flakes, you can hold them under water in your fingers and let them soak up tank water before releasing. I have found that some fish even become intolerant to certain foods after a while, so it is a matter of trial and error to figure out what they can eat without floating. Eliminate the flakes for a few days, and see if your fish floats eating other foods.

In any case, it would be a good idea to vary the diet of your fish. Add some peas to the diet which act as a laxative for godlfish. Buy frozen peas, and thaw them in the microwave by cooking for a 15 seconds or so in a bit of water. Pop them from the shells and squish the innards a bit in your fingers. The fish will love them. Feed them a couple of peas each, twice a week or so. Also, you can get a good quality pellet food. I would soak the pellets until soft in a bit of tank water, then squish and feed. I also feed my fish many veggies, such as lightly cooked zucchini, broccoli, cauliflower & potatoes. They also love bits of fruit such as stawberry & tomato. Other commercial foods you can buy are shrimp pellets, spirulina pellets and things like freeze dried krill. I soak all of these, but the shrimp pellets I only soak for a small amount of time, otherwise they fall apart.

I hope this helps, and please feel free to ask questions.