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It's been a couple weeks and I now have small seedlings started in the grow bed.  Figured I'd get around to testing the water.  I'm not sure what it all means though...

From a test strip, I get the following (readings an interpretation from the test kit)

Nitrate (No3) 40 ppm - safe

Nitrate (No2) 0.5 ppm - caution

Harness (GH) 300 - very hard

Chlorine 0 - safe

Alkalinity (KH) 40 ppm - low

pH 6.8? - neutral

I'm not sure I'm reading pH correctly.  It got darker a few minutes later, so may 7.8?

I also have two continuous read tests in the tank.  These are showing the following readings:

pH 8.0

Ammonia < 0.02 ppm

Temperature is 19C / 66F

I found the following table from some other posts.  Based on this, for a pH of 8.0 the fish is okay with Ammonia at 0.53.

Is there anything here to be concerned about?  I have gypsum that could be added to bring down the pH.  But maybe I should just wait until things settle in...


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You should read the strip immediately following the wait time for the strip. That's all I got for now.

you can always take water samples to a local aquarium/Fish store. (preferably saltwater fish store) tell them water your need tested for. most of them will do it for free.

I'm not much for test strips since they aren't as accurate as the vial tests, but I do think 8 is a better reading for the PH than 6.8 if you have hard water. They tend to go hand-in-hand. Most plants like a lower PH, closer to 7. As for the fish, it depends on the type of fish. What are you raising?

I have a single 5 inch gold fish in the 26 gallon tank.

Sheri Schmeckpeper said:

What are you raising?

I think your pH looks OK. I started out with a pH around 8, but after a couple months I was trying to find fish-safe ways to raise it because the nitrogen cycle had lowered the pH. I'm not an expert, but my limited experience says leave it alone unless your fish start dying.

The strip tests are notroiously unreliable... and with a general hardness of 300, and an alkalinity hardness of 40... I doubt that your pH is 6.8.... more likely it would be 7.8...

Tom, there are many known "fish safe" pH buffers that can be used to raise pH.... do a search for threads/posts containing "pH buffer"

Goldfish can handle anything, so I'm with Tom. Don't worry about it until your system is fully cycled. If you do lower it (we had to for a full year) you can use a tad of muriatic acid. Over time, your system should adjust, and sometimes cities change water supplies and your tap water might change, too.

Tom, ours fell dramatically and we started looking as well, but we decided to watch it instead. So far, after about 6 months, everything is still very content, so we're not trying to raise it anymore. We'll see, but I think it's found a happy point on its own.

I have compared the API test strips and with the API Freshwater Master Kit and, other than getting the Ammonia test strips for emergency use, the strips are way off of the Master Kit, sometimes enough that if I took them seriously I could severely damage the system.  For sanity David I would just get rid of test strips for a Master Test Kit, and as long as you follow the instructions you will sleep better at night.

Yeah, I have to agree...the test strips suck pretty bad from what I can tell. I've tested the strips against reagent (liquid drop) kits and in the case of pH, against digital meters as well...and the strips aren't very reliable.

Sheri, I would just like to add, lest anyone get the wrong idea, that unless you are topping up with all rain water or RO water, you are in fact buffering up your system every time you top up whether you realize it or not (unless you are topping up with very 'soft' aggressive low pH water. But I bet that is not the case).

You see nitrifying bacteria just cannot function below a certain alkalinity threshold. They use up available carbonate alkalinity just by doing their thing (oxidizing NH4 to NO3), so nitrification is always an acidifying process.  Once the alkalinity is 'used up' it must be replaced, and there is just no way around's just part of the universal chemistry behind the nitrification process.

Now, that said, when you top-up a system with water who's pH is high-ish (and therefore has a good degree of carbonate alkalinity), you are in fact 'buffering up' with calcium carbonate (or more precisely, calcium bicarbonate since that's what it's called when it's dissolved in water, but we'll just say they are the same thing).

I, like you, will probably never have to add a calcium buffer (like lime) to my system, other than the water that I top-up with since there is a lot of dissolved calcium carbonate in my (and many peoples) water. That should be enough to do the trick...but that still very much counts as buffering 

David - I would recommend using an API water test kit...screw the paper tests.  I've posted a link to the test kit I'd recommend.


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