oscar ph and chemicals.

Question

-Hey thanks chris really helped but i'm still a little confused about charchoal. Change it weekly all three packets, or don't have any at all unless there is a problem? I guess I'm wondering how much charcoal to replace and how often? Thanks again.--------------------------------------
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-----Question-----
I set up a 55 gallon tank about a month ago. I have two Oscars about 4 inches long. I'm using a Fluval 305 filter system and change the water once a week about 20%. The ph has been a steady 7.0 but recently been rising about 7.6-8.0 now. I don't know the ammonia or nitrite levels yet the master teat kit is on the way. My question is should the ph be rising and why or will it start going down the older the tank gets? my other  question is when I do a water change I'm using stress coat and stress zyme to recommend specs, is this the only time I should be using these chemicals? are  there better chemicals? My last question is the filter how often should I change the filter and charcoal and do I replace it all or just some? Any help would be greatly appreciated.
-----Answer-----
Hi Trevor;

All you need is Stress Coat. Products that claim to help the biological balance are a waste of money in my opinion. Stress Coat is a good all-around water conditioner that removes chlorine, chloramine, binds dissolved metals and helps the fish with stress. You only need to add it when you make a water change.

The pH should go down as the system ages. It's kind of weird that it's coming up now. Do you have any shells, limestone or coral pieces in there? If so, remove them because they can affect the pH and cause it to rise. Don't try to alter it with chemicals though. Chemical pH adjusters cause a roller coaster effect that is very dangerous to your fish. Even if it stays on the high side for awhile, the fish are used to it that way and it's just fine. A stable pH is what's important, not a certain reading.

Your filter should be left alone until it is flowing slowly.  Avoid replacing the media (pads, foam, beads, etc.), just gently rinse the crud off in a bucket of tank water. The filter media has beneficial bacteria clinging to it that consumes the fish waste toxins. If you replace the media, out goes the most important part of your filter with it...the beneficial bacteria. The carbon is the only media that needs replacing often. You can replace it every week while it's needed. I only use carbon in my filters when the water has a problem or it's a new tank. Once carbon has been in the filter being used for a week, it's little pores are full and can't absorb any more impurities. My 55 gallon has a fluval 304 and I actually don't do anything at all to it more often than every 8 weeks. Usually longer. The idea is not to mess with it too often.

Let me know if you need more help...

At Your Service;
Chris Robbins

Answer
Hi Trevor;

You are right on both accounts. Change all the carbon weekly, and don't use it at all unless needed for a specific purpose. Long-term use of carbon can remove bad things, but it can remove even good things from the water that your fish need. Carbon has also been known to re-release toxins once the tiny micro-pores become full after a week's use. That's why I stopped using it at all unless there is a problem with my tank water. It is just my opinion and there are experts who do not agree with this opinion. It has been debated for quite some time. I only use carbon to remove old medicine, to reduce odors during 'new tank syndrome', filter possible contamination from environmental toxins (smoke, room spray, etc.) and remove the yellowish color from using driftwood decorations. When those problems are resolved, I fill the carbon space in my filter with something else instead. Again, just my opinion, but my fish have seemed to stay much healthier and more vital since I stopped using carbon all the time and for too long several years ago.

At Your Service;
Chris Robbins