general tank questions

[tracey]

I have just done a water change of about 20% an am still having problems getting my PH correct. my ammonia levels are at zero and my nitrite zero although my nitrate is at 15PPM (mg/l) I'm working on that, it's my PH at 7.8 I'm worried about! altough my fish seem to cope with it at that level I can't help but worrie. I have put 3 large pieces of tuffa rock in there it has had no effect! why is this and is there a better way of getting it up to 8.3?
My other worrie is when i cleaned out my filter ther was lots of flea looking creatures in there? Are they something to worrie about or are they fine? My tang likes to eat them when they fly out of the filter!
~Thanks Tracey

[leebca]

One of the greatest and yet challenging things about saltwater aquariums is that there is so much to learn and see and experience. Regarding the 'fleas.' They are copepods most likely. They are a food for many different marine lifeforms (especially fishes). Don't worry about them.

BUT -- do clean out this filter frequently. If you see dirt in it, clean it. That means every day if need be. Besides a mechanicl filter, you also need a chemical filter. If you don't understand this, see the glossary: Glossary of FOWLR Terms

Regarding pH, you are probably missing an important bit of information. You see, what controls pH is the buffering ability of the water. If you don't understand this, that's okay. Just trust me.

The buffering ability of the water is controlled by three ingredients: Alkalinity, Calcium, and Magnesium. You need to test for all three using a good quality and fresh test kit, that tests using a titration method. If you don't understand this, then: get test kits for all three (one for each)where you add drops slowly into a measured water sample until you see a color change. Don't let anyone talk you into or sell you test strips. A waste of money.

Now here is what most hobbyists are told: Keep Alkalinity, Calcium, and Magnesium within certain ranges. But this is insufficient guidance. The hobbyist's goal is to keep each of these in balance with the other two.

You need a table that shows you what those balanced numbers are. You'll find the table in this post AND you'll find more information about what I'm writing about: What is Water Quality. I suggest you read this post for other good info, too.

Once Alkalinity, Calcium, and Magnesium are in balance, the pH will control itself and remain in the right range -- so long as you keep these three in balance. While doing this you need to seek out things that adversely affect pH. This can be dead or decaying things; dirt build up; bad source water; etc. So check these all out while you work on the balancing act.

Hope this helps.

[reeferguru]

When did you test your pH? Your pH level will be lower at night after the lights go off because photosynthesis has halted and carbon dioxide levels have increased.
How much live sand do you have? Live sand will assist in the buffering of your water as Leebca mentioned. Have you tested your alkalinity, calcium and magnesium levels?
Alkalinity and calcium levels work against each other if you do not add a two part or Kalkwasser solution or comporable. Magnesium levels should be three times what your calcium level is for optimal conditions.
Maintaining a stable and higher alkalinity level will help combat fluctuations in pH and enable you to have a better chance of sustaining a proper pH level in your tank. Alkalinity is nothing more than the ability of your water to reduce the chances of pH level fluctuations. Alkalinity has also been associated with coral growth as well but the major contributant is efficient control of pH swings.
If you add water flow to the top of your tank at the air water surface interface, open a window in the room your tank is at, add a ozonator-redox, these will enable you to raise your pH levels or you could add a buffer to raise your pH though this may be just a temporary fix to a greater ongoing problem.
The more dissolved carbon dioxide you have the lower your ph will be. The higher the dissolved oxygen level of your water, the higher your pH will beis a general guideline for your water and pH!
Good luck
Test your water and do it religiously weekly!