Fin Clamped Goldfish

Question
We have a goldfish (not fancy)and a shubunkin living in an unheated freshwater tank.  We have had them for 15 months and until a month ago they were both fine.  We have a filter running in the tank and do a 50% water change approximately every two weeks.  They are fed on dried pellets or dried flakes with occassional defrosted bloodworm as a treat.  About a month ago the goldfish started clamping its fins and sitting on the bottom a lot, occassionaly it madly swims and darts around the tank, sometimes banging into things.  The shubunkin remains fit and well.  My book suggested poor water quality so about a week ago I completely cleaned out the tank (using existing tank water) and replaced about two thirds of the water with fresh, adding back in about a third of the old water.  The goldfish is still fin clamped on the bottom.  I cannot see any white patches on it anywhere although the end of the tail fin seems to be split a little and there is a small black fleck on it that I'm not sure has always been there..  Otherwise I cannot see anything that appears to be an obvious sign of disease.  It is eating ok.  Do you have any idea what is wrong or what we might do next?


Answer
Hi Sarah,

Ahh, a book! Music to my ears! It's so hard to get anyone who is unwilling to, to buy/borrow an aquarium book, even though (in my opinion) this is the very best insurance policy against failure to provide adequate care due to lack of knowledge. Let me also say that there are some excellent sites and articles on goldfish care, some of which are real eye openers. For example, did you know that goldfish do not do so well on only dried foods? Read more about alternative things to feed your goldfish...raid your vegetable drawer!
http://www.wetwebmedia.com/FWSubWebIndex/gldfshmalnut.htm
http://www.kokosgoldfish.com/food.html

In any case, this is the first thing that jumped out at me - that you are not providing much or anything at all in the way of fresh greens, either aquatic or terrestrial vegetables. Goldfish are prone to constipation, so do not do so well on "community" flakes, even goldfish flakes or pellets from popular brands like Tetra, contain too high a protein content to be used all the time, every day. While these are fine treats, I would make this no more than 25% of the diet. Another 25% of the diet can be Spirulina flake, which is an algae based flake that is very healthy for goldfish and other vegetarian fish such as African cichlids.

The other 50% of the diet, should be a medley of veggies, either blanched, or frozen and defrosted, but if put raw in the aquarium, allow them to soften a bit before removing as some (such as cucumber or squash) have tough outer walls that need to soften before they are fully edible.

One food I highly recommend, which you will have to order online most likely, is New Life Spectrum. I use it on my cichlids and it is extremely palatable and nutritious for them. They never get bloated on this food, and their color positively shines! So I take it as proof in the pudding that it is a stellar food. It looks like this:
http://www.bigalsonline.com/BigAlsUS/ctl3684/cp18338/si1382519/cl0/newlifespectr...

All right, now that we've addressed the diet, let's concentrate on water quality. Do you have a test kit? It would be helpful for you to know a few water parameters. For one thing, goldfish like their water hard - they don't do well in soft water. So if your water is soft (with low alkalinity and hardness) then you need to buffer it up. I won't confuse you if you are blessed with hard and alkaline water, but you need to have a test kit to tell you if this is so! Hard and alkaline water is very resistant to change. It keeps the pH stable, this is what alkalinity does. So if your alkalinity is low, your pH will totter around, and fish do not like this one bit. They like stable water conditions, this is more important than concentrating on a "perfect" pH - which in goldfish, by the way, is about 7.2, just a little above neutral. So let me know your hardness, pH and alkalinity. A 5-in-1 test strip or liquid kit will say.

Another thing to test besides water chemistry is water quality. As you probably know, ammonia and nitrites are not present in an established tank that is healthy. So, if you see any of these levels (even if they are low) - there's trouble (!) and you need to do some water changes (in the magnitude of 50-75%) to make things right again. Nitrates are another story. Nitrates are present in every established aquarium at some concentration or another. Being the end product of the nitrogen cycle, the only way to remove them from your aquarium is to depend heavily on live plants to consume nitrate, or to remove nitrates from your tank by changing out water. How much water? Well, in a goldfish tank with a couple of large goldfishes, I'd say lots of water. 50% a week if this tank is of average size for two goldfish, you can get away with less if a bigger tank such as 55 gallon. Makes sense, right? Goldfish produce lots of waste, meaning lots of nitrate - remove this with water changes, and try to keep levels at ~20 ppm, and definitely <40 ppm.

What you didn't mention was...just how big is your tank? If this is a 10 gallon tank or less, then right here is your trouble. But since you've been reading, I hope you've got your goldfish in at least a 20 gallon tank, although this will be small as they become fully grown. A 29 gallon tank is just about perfect for two goldfish, so here's hoping your tank is this size or larger. Let me know!

Another point to mention is filtration. Those messy goldfish need powerful filters! If I had two goldfish, I would put them in a 29 gallon tank, and I would opt for at least 10 times turnover of the water, which means a flow rate of 290 gallons per hour (gph). This could be accomplished with two sturdy hang-on power filters, or one power filter and one small canister filter. I prefer not to run carbon in filters, because they take up what I consider to be extremely valuable space that is better used for biological and mechanical filtration. So in all my filters, I use some ceramic media (biological) and sponges (both mechanical and biological) and possibly some filter floss, which is basically the same as polyester batting (mechanical).

One last thing! An article that just came out in Practical Fishkeeping (a UK mag) is available online here:
http://www.wetwebmedia.com/FWSubWebIndex/goldfish101art.htm
It covers nicely what makes goldfish keeping "special", i.e. more challenging than a typical tropical community tank.

I don't know what to offer specifically for your goldfish, Sarah. Clamped fins is a vague sign, but I would be checking the water chemistry and quality as stated, expanding the diet...and another thing that might help is to add more oxygen to the water. The cooler water goldfish need and are supposed to be in, is higher in oxygen than a tropical tank. But there's certainly no harm in installing a powerhead and/or bubble wand or airstone in your tank to add more!

If you choose, you can add a bit of aquarium salt, as this helps certain fish to cope with stress, and goldfish are fairly salt tolerant. 1 teaspoon per 10 gallons should be enough. You can use any kind of salt, but preferably not table salt with iodine - rock salt, kosher salt, or "aquarium" salt (although it's a rip off!) will do.

Do write back if you need more information or clarification, I hope those points give you something to chew on. For the future, do know that a whole tank tear down is seldom necessary to bring water quality back up...just vacuuming the gravel lightly, servicing the filter, and doing a water change (30-50%) should do in most instances.

Take care!
Nicole