pH lowering problems and the accuracy of certain test strips

[lbr1022]

Hello,

We are setting up our first tank in anticipation of the blue crayfish who will soon be occupying it. It is a 20 gallon freshwater tank.

We live in an area with hard water and a relatively high pH. We filled the tank with tap water, added a tap water dechlorinator, let it acclimate, and then tested the pH with an API 6.0-7.6 range test kit (with the glass vial and liquid drops). The pH read 7.6. Even though I know most fish prefer a stable pH to a perfect pH, I was a little concerned about this number because we don't know if it means that the pH really is right at about 7.6 or if it is actually higher than a 7.6 but that's just what the test kit maxes out at. We ordered a higher range kit that has not arrived yet - hopefully tomorrow.

In the meantime the guy at the fish hobby store suggested we add 2 Tbsp of white distilled vinegar to the tank to try to naturally lower the pH since we don't want to use chemicals if it can be avoided. We did and the pH did not lower (as far as we are aware with the 7.6 max test kit) but it produced a bacterial bloom and white, cloudy, smelly water. So we dumped and replaced all the tank water with a new batch - this time 3/4 tap water and 1/4 RO water and 2 mL of tap water dechlorinator because, from research, we learned that RO water in small amounts can help reduce the pH. We tested again the next day and the pH on the API test is still reading at a 7.6. We tested the new tank water several times throughout the week and kept ending up with a 7.6 reading. Frustrated with the lack of results and wondering if the API kit might perhaps be faulty I took a sample of our tap water and separate sample of the tank water (tap & RO fusion) to Petsmart to be tested there. They used the Jungle Labs Quick Dip Complete Water Quality test strips, which rated our plain tap water's pH at somewhere between a 7.2 and 7.8 - which we can live with if we have to since know that once the cray is in there and eating that the pH will likely reduce a little more.

Then the Petsmart lady did a complete test on our tank's water and the test put them at the following levels:

Nitrate - 10, Nitrite - 0, Hardness - 150, Chlorine - 0, Alkalinity - 120, Ammonia - 0, and pH - 6.8

I went back home and retested the exact same tank water sample I brought to Petsmart and the pH on the API kit, again, read at 7.6 or higher. I have several questions:

1. There's a big difference between a 7.6+ and a 6.8 pH reading. Whose kits are generally more accurate - API or Jungle Labs Quick Dip? Do you think we might have a faulty API kit? How do we tell what's really going on here? I just don't know what to believe, and subsequently, if we have a problem or not. We don't want to get the cray until we can get this sorted out.

2. Are all the levels I listed above good for a blue cray's tank? I think they are, but we're also just learning and I want to confirm. I know stability is what's really important and not perfection when it comes to a particular number, but I do want to be sure that nothing is toxic.

3. Is it okay for us to continue using 3/4 tap and 1/4 RO with a dechlorinator but no water conditioner? Is the water conditioner really necessary or is it just another chemical thing we can skip as long as all the levels remain stable and safe?

4. We're taking the water samples to the fish hobby store that specializes in fish and tanks tomorrow and we're going to ask them to test the water for us as well to see what kind of a reading they come up with there. If their tests also show that we still have a pH problem, even after we added RO water, what else can we do to naturally lower the pH, while still keeping the level stable (buffering capacity I think that's called?) without resorting to chemical interference to lower it? Someone else suggested the white distilled vinegar thing again, but this time to dilute it in 16 oz. of water and very very slowly over a 24 hr. period add it into the tank so we won't end up with another cloudy white bacterial bloom...but I just don't know if that's a good idea.

Thanks for helping out a new hobbyist!

[jlk]

This is just my opinion, but use your tap water and leave well enough alone. Crayfish actually prefer harder, alkaline water and your tap sounds ideal. Ph ranges of 7.5 and lower actually interfere with their shells & molting. They are a very adaptable species. Heres a link for crayfish- there are many more with greater scientific information but this one covers the basics.

Crayfish

[severum mama]

I completely agree with jlk. There is no reason to try and alter your water chemistry- what you have out of the tap sounds great for a blue cray. I also wanted to add that test strips are pretty much garbage and I wouldn't trust those petsmart readings at all. The API kit you have is more tthan likely giving you much more accurate readings. Of course, it never hurts to check against over kits so there is nothing wrong with going to that other store for another test. Hopefully they will use a liquid kit rather than strips.