lowering pH

Question
is there a way to lower pH without buying something from the pet store as I am in between jobs and have kids. I have a 55 gallon fairly new tank with two oscars which I feed rosies. The tank is in a window for natural inderct sun does that have something to do with the pH? What is the proper pH for Oscars?

Answer
Hi Andrew
What exactly is your ph reading?  Just about all fish we buy will tolerate a ph of 6.0-8.0 just fine.  The key is keeping the ph stable, not having it fluctuate, which is usually what happens when you try to alter it.  The only time it's a good idea to alter the ph when it's in that range, is if you're keeping wild caught fish, which is becoming rarer, most of the fish we buy at the store are tank bred or farm raised.  And, it is more difficult to lower ph then it is to raise it.  The reason is because higher ph has higher concentrations of minerals which make the water hard, and it can be difficult to combat those.  Lower ph is more acidic and is usually lacking those minerals.    

Now, if you really want to lower your ph, you can add some driftwood, add some peat moss to the filter(both of those will most likely turn the water a tea color as well, which is fine), use RO water, or inject CO2 into the water.  I don't recommend those ph down/up products because there's more involved then just adding them.  But, the problem you'll have, your tank ph will lower, but when you do a water change, it'll raise again temporarily because your tap water ph is higher then the tank.  That fluctuation in the ph is enough to shock or even kill the fish.  So, you would need to "cure" your water change water in a separate container for a day or two before doing the water changes.  Some different set ups could be letting the water sit with some driftwood, or filtering it over peat, etc.  But with a 55 gallon tank....almost not worth the hassle, especially with oscars which can tolerate a wide ph range.

Honestly, if it's within that 6.0-8.0 range, even a tad higher then that is fine, then I would leave it alone.

Other issues I see though....I'm going to assume since you mention it's a fairly new tank, that the oscars are still small.  They grow to about 14 inches, and do most of that growing their first 9 months.  The minimum tank size recommended for one oscar is 55 gallons, with two at least a 75 gallon tank should be used-though larger is better.  I know you said you're not working, but definitely would be a good idea to keep an eye out on craigslist or lsn for a cheap used tank.  The problem with oscars, and I had an oscar years ago in a 55 gallon tank so I'm speaking from experience, they are messy eaters.  They poop large.  Water quality is very hard to maintain with a large oscar, even in a 55 gallon tank.  I used to do 50% water changes on my tank weekly, and it was still pushing the acceptable limits.  You always want your ammonia and nitrites to be at 0 ppm.  Nitrate levels reallly should be kept ideally under 20 ppm.  High nitrate levels can cause stress, leading to hole in the head disease-which oscars are prone to get.  I had excellent filtration on my tank as well, a large canister and also a large hang on the back power filter, and it was difficult to keep the nitrates low.  With two oscars, I would recommend doing two weekly 50% water changes-yes, changing out 100% of the water every week.  Only because, like I said, I know it's difficult to maintain those levels with one in that size tank, with two.....they'll be off the charts.  I don't know how your tank is set up, but I would also at this point recommend removing any rocks or decorations, even some of the gravel if it's a deep gravel bed to allow as much water volume in the tank as possible.

Another bad thing going on, which will also tie in as well with the water quality, is the rosey red minnows.  Bad idea feeding feeders to fish.  There's not much nutritional value in it for them.  They foul up the tank with the bits and pieces that aren't digested.  And, feeder fish from the pet stores is a good way to spread parasites, bacteria, and even algae into your tank/fish.  If anything, it's better to breed your own feeders for that reason, but still not a good idea to feed them exclusively.  Oscars also do require a varied diet.  Lack of a varied diet has also been proven to contribute to hole in the head disease in oscars.  And, when fish become used to eating feeder fish, it can be difficult to convert them back to "real food".  Their diet really should consist of a good quality pellet food, cut up pieces of shrimp, squid, or fish fillets, even rinsed off pieces of tuna fish is good for them, if they're still small-frozen bloodworms, frozen krill, frozen beefheart(can also buy this in the deli at the grocery store cheap and cut up and freeze yourself), algae wafers, shrimp pellets, worms(but not tubifex worms), once or twice a week feed them a pea as well.  Any frozen foods should be thawed first in a bowl with some tank water.  Oscars are omnivores-meaning both plant/vegetable and meaty foods should be fed, with mainly meaty/protein foods as the main food source-but not feeders :)  I know you're on a budget, but there are recipes out there as well that don't sound too expensive, and you can freeze them and they'll last awhile.  I haven't gotten around to trying them yet but they sound....good or healthy anyway.

Here's some links for you to look over:
ph, gh, and kh article:
http://www.chelonia.org/Articles/waterchemistry.htm

Good oscar forums/sites with additional info:
http://www.oscarfish.com/

http://www.oscarfishlover.com/index.php/The-Oscar-Fish/13925-feeders.html

Fish food recipes:
http://www.loaches.com/articles/home-cooking-your-own-frozen-fishfood

http://home.comcast.net/~76fxe/food.htm

Also here's a link that explains the nitrogen cycle if you're not familiar with it.  It talks about how the ammonia, nitrite, and nitrate levels go in a fish tank:

http://freshaquarium.about.com/cs/biologicalcycle/a/nitrogencycle.htm

Hope that helps and let me know if you have more questions.

Christy