Ph drops quickly

Question
I have a 55 gallon with an assortment of Mollies, guppies, tetras, swordtails, catfish, small snails, two big plecos and some plants. My PH seems to drop rather quickly. I use PH up and also do water changes to get the pH to around 7. I have read that feeding the fish two much can cause the pH to drop. I feed the fish 2X a day, once in the morning and once in the evening. Could this be the major cause of my PH to drop so quickly? The tap water PH is around 7.2.

Thanks,
Kevin

Answer
Hi Kevin,

There may be some truth to that...feeding lots of rich foods does put lots of organics into the water. Whether the food gets eaten or not, it gets processed as fish waste or decays - one or the other. While this breakdown does result in the acidification of the aquarium, it is probably not the main reason for your pH dropping.

The main reason your pH drops is probably because the alkalinity is low right out of your tap. Alkalinity is what keeps pH buffered. While pH up may help, there are better, safer, cheaper ways than using this product - just make yourself up a big batch of Malawi Salt Mix (MSM)!

Here is one recipe:
http://answers.yahoo.com/question/index?qid=20080121123900AAqP9ZL

I highly recommend you use marine salt instead of plain old sodium chloride...the other ingredients you can find at the grocery store. That's because marine salt is full of beneficial trace elements.

If you use 10 teaspoons instead of 1 tsp of everything, you'll have enough MSM to buffer your entire tank (assume your aquarium holds 50 gallons with decor, although probably a bit less). I wouldn't add this much at once, however...try adding some today and then some tomorrow. Altering your aquarium's water chemistry is best done gradually.

Then, depending on how much of a water change you do, always add MSM to the new water. This will be gentler and cheaper than using pH up...what you'll be doing is upping the alkalinity, adding carbonate hardness to your water, which will make your aquarium more stable.

Feeding different kinds of foods will help with the acidifying issue. Vegetables are high in fiber, low in protein, so they make a fantastic snack - for you and your fish! Your livebearers, plecos, and snails would all enjoy a slice of zucchini, curly or romaine lettuce, yellow squash or maybe just some cooked peas with the shells pinched off. (I used canned without salt, but defrosted frozen works well also.)

Less nutritious, but very tasty, are cucumber and melon or cantaloupe. These foods are mostly water so provide roughage but not much else - the same with adult brine shrimp, it's mostly water. I have found that a Chip Clip (the magnetic kind for refrigerators) works to keep the veggies weighed down. Nori, which is roasted seaweed that comes in sheets and is used for making sushi, is something that my fish like to pick at and it's very healthy. Weigh it down with a plastic clothespin, then retrieve the clothespin when the nori is gone.

All those vegetable foods will keep your fish feeling full without adding much pollution to your water. Protein rich foods such as flakes and pellets will acidify your water more than vegetables, so use these sparingly. I like to feed 50% dried foods like flakes and pellets and 50% veggies and frozen foods like mysis shrimp and bloodworms. The best flakes (in terms of palatability and ingredients) seem to me to be Omega One brand, and the best pellets are probably New Life Spectrum pellets, which are nutritionally complete.

I hope those suggestions help, take care!
Nicole