my roomates 55gal cichlid tank

[dork187]

my roomates have this really nice 50 gallon cichlid tank
the only cichlids left are one full grown electric yellow and one of its offspring
it also has one marble sailfin pleco, one yoyo loach and one clown loach
ive used my test kit on it and found that all parameters seems to be normal except for the GH and maybe the PH

pH  5.0 (maybe less)
GH   17-18  {!!!}
KH  0 {???}
NH3  0 mg/l
NO2 <.3 mg/l

its been established over a year and half and this problem has only been in the past month

could the problem be one of the rocks in there?
should i bring out each one and test them?

the GH is boggles me, with it being that high what does that do to the water?

any suggestions woould be appreciated
???
???

 

[ronrca]

First thing I do is buy another testing kit maybe even a different brand name just to make sure before I make any changes. Believe me, it has happened to me (same thing with thermometers). After that start with the decor. Does your roommate add any chemicals?

 

[Matt Nace]

Is your water filtered through a water softener?

Your Gh is high because you have calcium salts  disloved in the water( I am guessing). Your kh is 0 because you have no calcium biocarbonate in the water. This will bring your Ph down as well.

Your PH is too low, and you need some sort of temporary hardness, for it not to fluctuate, or be buffered.

What are your NitAtes?(HNo3)?

I am wondering also with a year the tank being up, why you have nitItes of any sort.

Tell a little more of your roomate's or your water changes, cleaning of the filters, replacing media, and as ronrca said, if any chemicals are used.

 

[dork187]

thank for your help you guys
does anyone have any suggestions as to what brand of testing kit i could
i dont have much money but i have enough to spend on a decent testing kit moderately priced
the kit im using now is the
"tetra test laborett"
they dont add any chemicals to the tank that i know of..
what can i use to buffer the ph? should i just do a 25-30 % water change, our tap water is in the 7-8 range
the nitrAtes are < .3  (effectively zero)
the nitrItes are  zero

im hoping i can get my roomates to pitch in on a testing kit that i would primareily use... its so frustrating for me to see such a nice tank go to $#!†

thanx again

 

[ronrca]

I dont buy the big master test kits. I usually buy pH, KH, GH, Ammonia, Nitrites and Nitrates tests. I like using Aquarium Pharm. and Hagen. They are reasonably priced at around $10/test.