Another pH, KH, GH Question

M

merlin4260

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Apr 19, 2003
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Purdue University
Alright, here we go...

I don't have my tank yet, but I got a water test kit to check my tap water to make sure that I would be able to have the fish that I have been planning for. What I have been preparing myself for is a 75g planted Angelfish community tank w/CO2, and after the tests I am dissapointed.

My pH is not bad at 7.2, that I can work with. My problem is in my KH and GH, both are very high at 18 and 23 degrees respectively (320 and 412 ppm). Which would lead me to say that my planned tank would not do so hot.

Now comes the confused part. Most everything I have read to this point has emphasized GH and KH as being just as important as pH, but in my searches for answers in Aquaria Central I came across this link http://www.tomgriffin.com/aquasource/hardwater.shtml

Which in a nutshell towards the end basically says that pH and stability are the main concerns and that KH and GH shouldn't pose a major health threat to the aquarium as long as things are kept stable.

So basically I am looking for HELLLLPPP!!! Is his oppinion valid or will I lay waste to my fish if I stick with my tapwater? I really don't want to have to modify my water if I can help it because this will only drive up my costs and time, but I also want to have a healthy aquarium.
 
LOL...Yep, that's about as valid a resource as you're likely to find. Fish can adapt to a wide variety of conditions, if acclimated slowly. Breeding can be compromised by widely different conditions, but the overall health and well being of the mature fish is based on clean water, and stable conditions more so than specific ones. The plants will also help, and the CO2 will drop your pH a tad as well.

Also, there are two kinds of angels, one which is captive bred, and very hardy, the other which is wild caught and more sensitive to parameters. Sorry--I can't help more. I don't know the different names, not really an angelic type. ;)
 
Whhheewww...(sigh of relief). I know that certian fish are picky about water conditions when it comes to breeding, but I'm not concerned with breeding my fish. I'll be happy so long as they can be healthy with my tap water conditions.

Another question that comes to mind, according to my measurements straight out of the tap and another excellent link I have found through aquaria central Chuck's planted aquarium page my Co2 levels from the tap are at 34ppm. (which oddly enough I almost believe because if I leave a glass of tapwater out over night, the sides of the glass will be covered in bubbles in the morning) but that still seems unrealisticly high. Is it more realistic that my tap water may have some phosphate buffering which would make the CO2 chart invalid?

I also tested some tap water which has sat out for a week or two and its results were pH=7.6, KH=16 degrees, GH=22 degrees, which equates to 12 ppm CO2. Any thoughts?
 
Planted tanks don't care what the GH is as long as there is some calcium and magnesium present for them.

Soft water fish do prefer low-GH water to breed - has to do with the egg membrane response to the Ca/Mg ions. Standard Angels (Pterophyllum scalare) in their many color morphs have been bred in captivity under so many different condition for so many generations, that they are not so picky anymore, but your GH may be a bit too high even for them. The Altum Angelfish (P. altum) are all wild caught and picky as the devil. Don't even think about trying these fish unless you are an expert in water management.

Planted tanks don't mind high KH water either, so long as you can get some CO2 to dissolve. BUT, there seems to be some problem with your test results - may I place a bet that you tested water fresh from the tap? You are showing ~30ppm or more dissolved CO2 with that pH. Tap water pH test must, repeat must be done on water which has set out 24 hr in a shallow bowl to equibrate to atmospheric pressure and dissolved gas levels. Cold pressurized water can and does dissolve much more gas than water equilibrated to ambient pressures and temperatures. Alternately you may aerate it strongly for 30 min or so.
 
Okay, we cross-posted.

Your water is still off somehow. Max sea level CO2 is on the order of 4-5ppm.

Most of the bubbles you see are nitrogen (~80% of air) and oxygen (~20% of air) or more accurately a combo of them - air dissolves, air comes back out, but may be partly segregated dependent on solubility of the various component gases - CO2 is much, much more soluble than O2, but there is much, much more O2 in air, etc.

Call the utility and get phosphate figures, see it they pH "shock" the water ...you may want to review WetmanNY's site on water also...

http://www.skepticalaquarist.com/

If your water is shocked, it takes even longer to stabilize...

HTH
 
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CO2 gas off is v ery normal. The CO2 builds up in the water as it is pushed around the pipes to your tap. Without the pressure, the gas comes off, and the pH will climb as well. The results from the water that has sat out are closer--but I would take a glass, let it sit 24 hours and test. This will be you pretty close to what you can expect 'normally'.

Of course, I'm not the chemist in the house, so these explanations are simplified enough for me to understand them. RTR or wetmanNY will be able to explain things much better.
 
:D

And people wonder why I am confused when I hear complaints that no one answers questions here!

Hope we are not overloading!
 
Definitely not overloading, I am one of those people who has to know EVERYTHING I can get my hands on b4 I sink a conisderable amout of $ into a hobby. The more the better :)
 
Also, RTR, you are correct in that the first set of readings was directly from the tap. The second set however has sat out, and I was just using the glass for an example of the gas content in my water. Also the test kit is brand new, so I know it is still good.
 
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