I just moved to the Dayton area and found that although the nitrate level in the tap water is near 0ppm, the water is hard/very hard. About a year ago I got an RO+DI unit to remove the nitrates (for the fish) and to soften the water (for my aquatic turtle), and now I'm wondering if I can just use Prime-treated tap water for the fish. I have bolivian rams, cory cats, black skirt tetras, a dwarf gourami, and a BN pleco. Would hard water be bad for any of my fish or plants?
is hard water ok for a community tank?
- Thread starter hbeth82
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rich311k
Aquarium Advice Addict
How hard is it? Most fish will adjust to it.
jcolon
Aquarium Advice Addict
Do you know what's the pH of the tap? Fish will adapt to a high pH due to the minerals. Our water here in Long-Island is relatively hard (groundwater) and it doesn't bother my fish at all.
If you acclimate your fish ... they should adapt to the tap fairly well ... same for my plants.
If you acclimate your fish ... they should adapt to the tap fairly well ... same for my plants.
According to the county water quality report, the GH ranges from 180 - 250, and my tap water was at the high end of that spectrum. pH is just a hair above neutral, about 7.0-7.2. When I moved down here most of the water I used for the fish tank was either RO+DI water or water taken from the tank before moving. They probably got about 10-15 gallons of tap water and seem to be doing fine.
mfdrookie516
Aquarium Free - 2+ Years
My tanks are 7.8... no issues
Bl80
Aquarium Advice FINatic
my tropicals didnt seem to mind, they kept on breeding when I moved to the city and the water is much harder here than it was there....
I'm not worried about the pH, seems like that close to neutral is fairly ideal. I'm concerned with the water hardness - I don't know whether my fish would be harmed by water with a GH around 210+. I had hard water at my previous place and they seemed to do okay then but wanted to double-check.
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pantherspawn
Aquarium Advice FINatic
Here's a nice post and general rule of thumb concerning Ph and alkalinity http://www.cichlid-forum.com/articles/hardness.php
That site helps, thanks!
mfdrookie516
Aquarium Free - 2+ Years
Sorry, should have been more specific. My water is very hard, which is why the ph is high (from the way I understand the chemistry behind it... more buffers = harder water and higher ph... maybe that's just kH).
pantherspawn
Aquarium Advice FINatic
mfdrookie516 said:
Its possible to have low Ph with alkaline water. Not common it would seem. But possible
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I understood that there was a link between water hardness and pH but wasn't sure how it worked. The last time I checked it, pH was good but the hardness was quite high (20+ drops using the API test kit) and nearly 0 nitrate, but I'll check it again soon before deciding to stick with tap water.
mfdrookie516
Aquarium Free - 2+ Years
It's all very confusing to me. I think hardness can be described as either the kh or the gh, which is what further complicates things. I was basing my statement on kh, which typically correlates with ph. But, as with almost everything in this hobby, there are exceptions to that. I think the basic moral of what I am saying is that if the ph is stable and you acclimate your fish properly (drip or at least adding water to the bag while floating) for a good while, you shouldn't have any issues.
As I understand it, kh is kind of a sub-set of GH. I can't remember if KH is the stuff that goes away when the water is boiled or the stuff that's permanent, but then GH includes both the permanent stuff and the stuff that can be boiled off. As for the pH, all I remember about that was happiness in chemistry class when my solution changed to the right color 
As for the acclimating the fish, I took about 90 minutes to do it, adding & removing water to the cooler I'd used to move them down here. Very thankful that I didn't loose anybody along the way and everybody seems to be doing fine, eating as usual and color looking good. I'm hoping that since most of the water they're in now was the RO+DI water, through PW changes I can gradually get them used to harder water. Also thankful that I held on to those bottles of Prime, though I forgot how bad that stuff smells!
As for the acclimating the fish, I took about 90 minutes to do it, adding & removing water to the cooler I'd used to move them down here. Very thankful that I didn't loose anybody along the way and everybody seems to be doing fine, eating as usual and color looking good. I'm hoping that since most of the water they're in now was the RO+DI water, through PW changes I can gradually get them used to harder water. Also thankful that I held on to those bottles of Prime, though I forgot how bad that stuff smells!
Ickletas
Aquarium Advice Freak
If it helps my water is 285 ppm CaCO3 (calcium carbonate) and my fish do fine (tiger barbs, giant danios, banded rainbow, blue rainbows, columian tetras, corys, siamese flying foxes and random sucking loach)
