Can this happen?

test strips

Hi.

I was using those strips daily at the store to test the sumps of our freshwater systems. 5 sumps total. Goldfish, African cichlids, The sewer (predators) Tetra pod CA/SA cichlids.

I would use the strips Monday through Thursday then test with a liquid tester on Friday. Over time I was noticing more and more that the strips were becoming unreliable as they got older. The kicker was when the strips were saying that all of our PH's were out of wack.

While everyone was panicing I retested using the liquid and found that all was normal. It seems that the strips tend to get contaminated very easily. I quess from when you open it and place your hand in the container. I really am not sure though. Could very easily be the amount of humdiity in the air???

First sign is when the alkilinity starts to show 2 colors one round one in the middle and another on the rest of the blotter. Then slowly the others start to do the same.

The only blotter that I have found tended to be relaible was the NO3 (most times than not it was close or very close) the rest were usually off. Sometime slightly other times vastly.

So.

Before getting worried. Bring your water into your LFS for testing. See what they say. Or if you have the liquid tests, retest the rest yourself.

Then make your judgement from there. I have a feeling that you may not be in as rough situation as those strips are telling you.

Good Luck.

Plese post the Liquid results. I am curious to know the final outcome.

PH

Hi.

7.2 is almost netrual. Not really alkiline

Sometimes the hot water out of the tap will give a higher reading until it cools.

One easy method to lower ph is to place peat moss in your filter. It will lower the ph gradually. Just keep in mind when you are doing water changes that the ph in the tank will rise a bit depending on the amount of water being removed and replaced.

Why do you need the ph lowered? Neutral water is fine for most fish. Are you going with discus or cardinals etc?

Here's a pretty good link on PH

http://www.thetropicaltank.co.uk/ph.htm

And one on water hardness and its effects on ph

http://www.aquariumpharm.com/articles/gh-kh.asp

Originally posted by wengdragon

so here are my questions:
1. How exactly are these ph testing kits work? one thing i know is that our water has iron in it, can that effect the result of the ph test. Can both companies' product sgive me the false reading?
2. if the test kits didn't lie to me, how to lower the ph once and for all? will adding those ph down product fluctuate the ph too much?
Thanks for any answers

Click to expand...

From a somewhat more scientific perspective for Q1...
1) pH meters actually work by measuring electrical current I believe. As for pH testing solution/strips, they are simply certain chemicals that change color from one to another at a certain pH (range). For example, potassium permanganate change from colorless to dark purple, or bromophenol blue changes from yellow to blue. The pH test strips are simply made by "sticking" these chemical on some sort of (paper) support. The problem with consumer level pH strips is that they'r cheaply made and the chemicals are only loosely bound to the support. The chemical can (and will) become loose and may actually affect the pH ITSELF. This becomes more important as the sample (tank water) volume is very small (only a drop of water on the strip) thus becomes more easily affected. That's why you'll see 2 color range (center and surrounding of water drop has different colors) sometimes. In research lab, we have pH strips (tho rarely use them) that are made by covalently binding the chemicals to the support, thus making the strips more stable and accurate.

Keep these strips dry and dont' touch with ur bare hands, for (abit) more accuracy. I doubt if any level of iron in drinking water will affect the color of those pH test. It's more likely the buffering ions that's affecting the pH result, as stated in ur pH strip manual. If I were to bet, I'd say the pH solution test u had is more accurate. just my 0.02 tho.