I am really desperate. I have been trying so hard to keep our gold fish alive and so far Ive been able to do it-up until last week. I regularly read the boards here so I try all the advice I see. I soak the flaked food. Ive switched to floating pellets which I also soak. I run 2 wisper filters with bio sponges in them for a 40 gallon tank. I have medium sized natural gravel. We used to have problems with acidic water so we added shells and crushed coral...For the past 6 months it seems like nothing I do makes any difference. I have a very large fancy calico guy, Snootchie who we have babaied for the past 8 years or so. We (had) a large orange guy, Nineth, with a stubby tail and oversized body. He was beautiful. H e would have swim problems and float upside down all the time. peas seemed to help him. WE had 3 lion heads and 2 of them were lost to dropsy a year ago. The lasy one, Pearl seeemed like he was hardier. Then he started floating tail up on the bottom. Snootchie also srted having swim problems at this time. I change about 25-40% of the water every 2 weeks and syphonn the bottom at that time. We have a great water filter on our tap and I have always used the water straight from it. When Snootchie began having problems I began to get frantic. The amonia level is 0, the nitrate 0 and the ph is all the way at the top of the chart! After 2 weeks of ripping my hair out and a complete water change out of desperation when first Noneth and then Pearl died I realized that my tap water is actually alkaline, it never used to be!
Snootchie hangs out on the bottom and he looks stressed. Streaked fins with some fraying. He eats fine, but doesnt do much else. Im desperate please help! I also have 3 cordys(catfish) and a chinese algae eater, they of course are fine...

Marveeny,
First off, I would remove the seashells in the tank right away. Crushed coral and seashells are causing the extreme pH fluctuations which are stressing your fish out. They break down in the water and mess with the pH. The more your fish are stressed, the more of their slime coat breaks down, leaving them prone to illness. If you are having problems with acidic/basic water use a controlled ph buffer like 'ph up' or 'pH down' to bring the pH to acceptable levels.
Second I would do a 50% water change after the seashells are removed tonight, and over the next several days do a 20%-30% change daily. Keep an eye on the pH readings, and if you get them... use the pH controllers to bring your pH around 7-8.
I am hoping that once your water parameters are 'good' the fish will start improving. You could also add a little salt (keeping an eye on pH) or maybe stress coat to improve their immunity to disease. And if they look stressed, just turn off the light, it will help them out a bit.

In addition, I looked up what Brita tap water filters could potentially do to fish water, and although the hardness of the water will decrease with a brita (which makes the water taste good to you) the lowered hardness only (slightly) lowers the buffering capacity of the water against pH fluctuations. Thats it, no other changes to the water itself. So you don't really need to use it unless your water is *really* hard. The fish don't care.... Anyone feel free to correct me on this if I am mistaken.


Hope this helps....

As Obsidian said, remove the seashells and crushed coral immediately as these will make your water extremely hard and high in pH; if your pH reading is highly alkaline already then these are a big problem. Water changes with these in the tank will only make the matter worse because the pH keeps dropping, rising dropping and rising again, which no fish can tolerate. Once the shells etc. are out, then perform a series of small water changes over the course of a day or even two days - 10% or so at a time - to slowly bring the pH back down again without stressing the fish too much.

Test the water from your tap - what pH is it exactly? Anything between 7 and 8.5 is OK, as long as it doesn't fluctuate. If it is somewhere between these two then you don't necessarily need to add anything to keep the pH regular, but it would help if you could get your GH and KH tested (get this done at your local pet store), and find out exactly how well your water is buffered. If it has low buffering capacity then you can ether use the pH buffering agents which Obsidian mentioned, or you can use simple old household baking soda; add this a teaspoon at a time until the pH is about 7.5 and it will keep it there. You will have to add more soda or agent every time you do a water change though.

Can you find out the pH, KH and GH or your tap water and post the results here?

One last thing: OBsidian is quite right about the Brita filters; they don't actually remove much of the hardness from water - you may as well not use this for the tank. You do use dechlorinator though don't you? I only ask because you didn't mention it.