Tap water test results

[OldTimeFisher]

Hello,
As I stated in my introduction, I am in the process of converting my 90g saltwater reef tank to a fresh water aquascape. I am also in the process of sourcing new equipment, such as lighting, filters, substrates, driftwood and other various freshwater needs. I started with freshwater about 50 years ago and switched over to saltwater for the last 15 years. So I am a bit rusty on my freshwater skills and I love how far along the technology of freshwater has come over the past 15 years.
So today I received my new freshwater API master test kit along with a gh/kh test and a calcium test kit. I tested my tap water today and the results are as follows;
pH - 8.2
Amm. - 0
Nitrite - 0
Nitrate - 0
KH - 8
GH - 2
Ca - 20
If I remember the calculation right, gh ÷ 17.86 = dgh
Is this correct?
Also just wanted to get feedback on my tap water results to see if anything looks out of the ordinary.
Any feedback is welcomed!
Thanks!

 

[Byron]

Welcome to TFF.

If I remember the calculation right, gh ÷ 17.86 = dgh
Is this correct?

If the GH number is in ppm (or mg/l which is the same), dividing it by 17.9 will give the equivalent dH. In reverse, multiplying dH by 17.9 will give the equivalent ppm. Using the API test, one drop is 1 dH, so a GH of 2 is 2 dH (= 35 ppm). This is very soft water (I'll come back to this). Same formula works for KH, so the KH here is 8 dKH (= 143 ppm).

The 8.2 in pH needs to be looked into, as given the low GH I would suggest the water authority adds something to raise the pH (prevents corrosion of pipes, etc) which is common in soft water low pH areas. You might track this down on their website. Where I live, soda ash is added and this dissipates out within a day or so.

Back to the GH (and corresponding pH), with freshwater fish you need to match their requirements with the source water. The oceans all have the same parameters, so marine salts provide what is needed regardless of tap water. But as you have very soft water, the fish species that naturally occur in such water will be fine, but those requiring moderate hardness will not. You may alrady be aware of all this, so I will not say more unless asked.

The ammonia/nitrite/nitrate at 0 is perfect. You always want ammonia and nitrite to be zero, and nitrate as low as possible; nitrate will likely rise with time, but keeping it as close to zero as possible is better for freshwater aquarium fish.

 

[OldTimeFisher]

Thank you @Byron. I forgot to mention that I did leave the water to be sampled out on the kitchen counter over night in a glass jar.
I am also puzzled by the ph. I will definitely look into my local water authority to see if they are adding something to raise the ph. I do know that the water is from a deep well. It is pumped up 1000 feet from a artesian aquifer into a water tower that supplies my neighborhood and 3 others.
If I remember correctly, dkh should be between 4 & 8 as a rule of thumb, correct?
Would it be a good idea to add some type of mineralization to increase the hardness such as crushed coral? Although this would increase my ph also right?

 

[Byron]

If I remember correctly, dkh should be between 4 & 8 as a rule of thumb, correct?

No, not really. It is true than many species of soft water fish can be kept within this range, but a lower GH (zero as I have) does not exclude them, generally speaking. Species requiring harder water though (livebearers, some rainbowfishes, rift lake cichlids to name generally) would not fare well in water with a GH below 10 dH or some higher. So there is nothing wrong with your 2 dH water for soft water species...but that does bring up another question.

Do you have a water softener? Sometimes a quite low GH combined with a fairly high pH can be due to a softener than reduces GH. Worth knowing, as there are problems with most of these for freshwater fish.

Would it be a good idea to add some type of mineralization to increase the hardness such as crushed coral?

No, definitely not...provided you stay with soft water species (and subject to the water softener question). GH, KH and pH are closely connected as you probably know, and messing with one of them is always a recipe for trouble, if it is not done correctly. And yes, adding crushed coral would increase the pH. Crushed coral is also not a suitable buffering agent anyway. You need something like dolomite to safely buffer, but yes, this raises pH. I did this in two large tanks back in the 1990's, but then my water was not only zero GH/KH it was around 4-5 pH. But in hindsight, for soft water fish such as I maintained, this was not worth the trouble.

 

[OldTimeFisher]

No, I do not have a water softener. So I guess it would be safe to say that I have my pick of fish boring hard water species.
I'm looking to evolve my tank fish around a pair of German Blue Rams. My wife and I are wanting to keep our fish selections to South America species.
Would any of the water parameters listed above keep me from this goal?

 

[Byron]

No, I do not have a water softener. So I guess it would be safe to say that I have my pick of fish boring hard water species.
I'm looking to evolve my tank fish around a pair of German Blue Rams. My wife and I are wanting to keep our fish selections to South America species.
Would any of the water parameters listed above keep me from this goal?

Th pH is something of an unknown. The GH is ideal, but the question is, how are they raising the pH? And with a KH of 10 (presumably the API test so this is 10 dKH) this is fairly significant buffering capability. As the aquarium stabilizes and establishes (the next phase after cycling) the chemistry works itself out and it is necessary to see what it will do. Having said that though, a stable pH is easier on fish than one that fluctuates more than a few decimal places.

The other issue with the common or blue ram is temperature. It must have warmth, in the 82-86F/28-30C range, no lower. This will impact possible tankmate species, as many of our "tropical" freshwater fish cannot manage this high a temperature long-term. This is a 90g tank, which means considerable space for many fish, and finding only warmer water species to fill it will not be easy, if variety of species is also something you would like (and most of us do). The Bolivian Ram might be a better choice, though there are other similar fish (similar meaning colourful, sedate, something of "centrepiece" in nature), like gourami (Pearls are strikingly beautiful).

Something just occurred to me with the API GH and KH tests...did you count the drops up to the first one that even minimally altered the colour? Other members have sometimes added more drops than necessary, thinking the colour change has to be significant; but as soon as the colour from the first drop even faintly begins to change, you should be at the number. The KH test I found rather difficult to see too...holding the open tube vertically above a white surface and looking down through the test tube for many is easier to discern colour changes.

 

[OldTimeFisher]

GH is ideal, but the question is, how are they raising the pH?

I am researching this as we chat to see how my water authority is raising the ph if in fact they are.
I will let you know as soon as I find out.

Something just occurred to me with the API GH and KH tests...did you count the drops up to the first one that even minimally altered the colour?

Yes I did. One drop at a time. Then gently mixing the vial with it capped in between drops. The gh turned a very faint tinge of green after the first drop. I added another drop just to make sure which it turned a more noticeable green. So I guess you can say that the gh is exactly a 1.

The Bolivian Ram might be a better choice, though there are other similar fish (similar meaning colourful, sedate, something of "centrepiece" in nature), like gourami (Pearls are strikingly beautiful).

You are correct about the Bolivian Ram. This would be a better choice for the temperature of other capatible fish. The Bolivian Ram is a close runner up for us and I think this is what we will center the other species around. Thanks for bringing this to my attention.

 

[Colin_T]

Why don't you use the lights and filter from the marine tank for the fresh water tank?

 

[OldTimeFisher]

Why don't you use the lights and filter from the marine tank for the fresh water tank?

I could but they are t5 bulbs and I'm really liking the Fluval Plant 3.0. As for filtration, what I have been using for the reef tank is a 55g sump/refugium with a return pump in the bottom of the stand. I'm going to reclaim the bottom of my stand for a 20g quarantine tank that will also house additional plants for grow out and/or to sell. This will also give me plenty of storage room underneath for tank supplies and a Fluval FX4 canister filter.

 

[OldTimeFisher]

@Byron, I got in touch with my local water authority. He told me that they do not add anything to the water that I receive except for chlorine.
That the ph of the water is what comes up from the artesian aquifer. They do not add anything to adjust the ph. So this is good news!

 

[Byron]

@Byron, I got in touch with my local water authority. He told me that they do not add anything to the water that I receive except for chlorine.
That the ph of the water is what comes up from the artesian aquifer. They do not add anything to adjust the ph. So this is good news!

OK, so once you have the tank set up, monitor the pH and you should see what can be expected.

 

[Essjay]

The gh turned a very faint tinge of blue after the first drop

If this is the API tester, GH doesn't have a blue colour

GH turns from orange to green
KH turns from blue to yellow

 

[OldTimeFisher]

If this is the API tester, GH doesn't have a blue colour

GH turns from orange to green
KH turns from blue to yellow

@Essjay, I stand corrected. It was the green that I should have made reference to and not the blue.
(The first drop turned a tinge of green is what it should have read). I never did see the orange color.
I have edited post #7 to green as to not confuse anyone else. Thank you for catching my mistake.

 

[Byron]

The water in the tube being clear and turning a green tint with the first drop, i.e., not becoming orange at all, would mean the GH is in the zero to 1 dH range. My water does this. It is the KH I would want to check in your case as 10 dKH is high.

 

[OldTimeFisher]

is the KH I would want to check in your case as 10 dKH is high.

The KH was actually an 8 but I will recheck it and let you know. Thanks!