Regulating pH

With new unestabilished tanks, you should definately test for ammonia and
Ntirite, with estabilished tanks that aren't undergoing large changes it isn't necessary however nitrAte is something you should test for to estabilish maintenance needs. Any time anything goes wrong i.e. fish death, ammonia and nitrite should be tested for.

Ideal PH is a myth hands down no two ways about it. Even if it weren't a myth ideal would be somewhere in the 7.6 range for a good stable tank. Anything in a bottle that claims to lower PH or stabilize it either one is generally snake oil and will cause you much Gnashing of teeth. Ph can be raised fairly effectively by adding carbonate or bicarbonate (crushed coral, baking soda, dolemite etc.) however you should not tamper with these things without a KH test kit, as too much of anything will also cause you trouble.
If you are on rainwater, most likely you have little or no carbonate in your water. What you do have will be consumed by the natural processes in the tank, and thus lower your ph. Eventually your Ph will crash pretty hard. Read anything you can find on OTS (old tank syndrome) and remember a tank doesn't need to be old for OTS to be in effect.

Raising carbonate (Kh) quickly can be stressful to your fish. I would suggest a series of 10% water changes until the tank and tap read identical levels. You should put some tap water in a shallow bowl for 24 hours and then test Ph. There are often processes in our pipes that alter Ph, and letting the water stabilize with the air will give you true correct readings.
Once your tank and your tap are equal then you can work on adjusting to a stable level that you want.
IMO Kh should be around 2-3 degrees minimum, some folks would argue that it isn't necessary to be that high in a non-planted tank, but I like stability and 3 degrees seems to be the mark IME.
If you don't have a KH test, use your Ph for a reference. Start with very very small amounts of baking soda in your small water changes For a 10 g I would suggest 1/16 teaspoon of baking soda in a gallon of water, and then do a water change. repeat this process for several days until you reach something in the range of 7.4-7.6 and then figure out how much baking soda you need to keep that level based on your maintenance schedule. If you find that Kh/ Ph is lowering between water changes, a small amount of crushed coral bagged and in the filter will counteract this. Do not add baking soda directly to the tank, it is very fast to dissolve and swing kh/ph levels. Your fish will not like rapid swings.
HTH
Dave

Welcome to AC!

If your fish are living well at 6.0-6.2 DO NOT fuss with the pH, because the more you try to fuss with the pH, the more stress it is on the fish because of the flucuations (going up and down).

These pH altering chemicals that you see on the market are A WASTE in my opinion/experience. They will alter the ph only for a short time, and then it will go right back to where it was originally, and if you look ask around here or any other place, people will usually tell you this "A stable pH is better than a constantly swinging one".

If it were me, I would leave the pH alone, because tetras and rams actually prefer acidic water. (which your pH seems to be) because that is where they are originally from in the wild (the amazon generally has soft, acidic water).

If you need to alter the pH for any reason at all whatsoever, then use natural products (they are much safer, and actually work!).

If you ever need to lower the pH, you usually hear of people use Driftwood or Peat.

If you ever need to raise (buffer) the pH you usually hear of people using things like Crushed Coral or Limestone.

Hope This Helps at least a little bit!

FYI, blue rams and most tetras prefer soft water with low PH. Fishes will adapt to the PH lvls as long as its relatively constant, I have blue rams in PH of 7.6 and they are fine. What you don't want is the PH lvls changing drastically as that can kill the fish. Test your water right after you do a water change and then test it throughout the week and see if there's a noticeable change. If it does not then PH isn't likely the culprit in your fish deaths. If it drops by over .5 then its a good idea to buffer it by putting a little crushed coral in the water or filter.

The likelier culprit are the ammonia, nitrite, and nitrate lvls. ammonia and nitrites are toxic to fishes even at low lvls, nitrates are a little less so but needs to be monitored as well. You definately want to know these lvls and do water changes once they get to a certain lvl.

I used baking soda...about a tbs per 15 g of water. I eyed it and then tested the water before adding it to the tank. thing is I don't think it is stable...I mean that I was worried that it would build up or be filtered out causing constant shifting. I also bought a pH up chemical, but had no directions on ammount. I am just keeping my pH at what my water is rather than changing and fluctuation all the time. If that helps.

I also used something that was a neutralizer...it put it up or down, for whatever your tank is, but that seemed a waste of money.

You want fish to be equiped to deal with the water you have, don't just average it out and hope everyone is happy. same with all the other conditions...temp, salt, etc.

It seems from what you say, that store B might be wiser. Research on here, ask, ask, ask, and see how it compares to what the store says. ppl here are good. If they match opinions, then you got your store. Also, find out about details. Knowlegable stores will know fish vocabulary and you will see who knows what they are talking about if you go in knowing about hte processes, even if you don' t know the solutions.

good luck.

I would tend to agree with Pet shop B up to the point of the water being too hard. Chances are that your water is too soft if anything, and as pointed out this wouldn't be the cause of the fish death.
Ideal is to match your tank and tap so that water changes keep things perfect. If it proves that you don't have enough Kh from the tap to keep it stable then refer to the earlier post. Stability is the primary key IMO, and matching to tap is the secondary key. I have had trouble keeping my tanks stable at less than 3 DKH and I do weekly 30-60% water changes. Either way avoid the stable ph powder, and anything that claims to lower Ph. The stuff that claims to raise Ph is essentially baking soda at an inflated price, so don't waste your money there.

It is very common to get bad and conflicting advice from fish stores. Don't hate them for it, just do your research and learn the facts. of the three LFS's that I frequent there is only one that gives good accurate advice about much of anything. It took me quite a while to learn to trust them despite the good advice.

Taking a water sample in isn't a bad idea at all, get the Kh levels the Gh levels and anything else they offer to test for, and keep track of them. I do this routinely to verify my own test kits. Just don't let them sell you a bottle of anything without researching for second opinions.
Dave

1- GH- water hardness- 2*
2- KH- buffering level- 10*
3- pH about 6.8-7

Can you get your own test kit?

I would be concerned that this guy is going to try ti sell you chemicals that you may not need, or could get a cheaper version elsewere.