My 125 gal tank has been running for a month and I'm using wet dry filtration in a sump. the last time I thoroughly vaccumed was last week. Now my tank seems cloudy today so I am going to replaced the filters and do a water within the next 2 days..
I'm guessing you meant PH? Otherwise I'm not sure what GH is.
a Month???
Could be an ammonia spike. My Suggestions:
-Stop Feeding them for a few days to a week to let the BB Colony catch up.
-Leave Filters running and Do Not change them as you will remove the Built up BB. (cloudiness is a Bacteria Bloom trying to balance the tank out.
-Use a Master Test kit and keep and eye on your Ammonia, Nitrites and Nitrates as this is a very new tank.
-Do 25% water changes daily and use a Dechlorinator like API Stress Coat, Sea Chem's Prime of Safe.
I also use 1tbsp/10g of Aqaurium Salt and Epsom Salt (Mag-Sulfate) but the ES is more for Raising the Gh as it optimizes Adult African Colors and also Keeps Bowel Movements regular. I have mainly Tropheus...
If you can... Pull some media from an Established tank and rinse it out inside the 125. it will get dirty looking but will clear up in 24hrs and put the nitrogen Cycle in Check! If no other tanks, Head to the Local Fish Store and ask if they can give you a bag or cup of rinse water from a healthy tank of theirs and you can pour that right in the 125g and it will do the same thing.
NOTE:
Gh is for "General hardness" and is basically the mineral content in the water (mainly Magnesium and Calcium though). Africans require between 8-20 (Dutch Scale) or 145ppm (8 x 17.9 clark scale) to 358ppm (20x 17.9 CS)....
Kh stands for Carbonate and Bi-Carbonate hardness and that is basically the buffering capacity of your water. These will absorb harmful acids produced during the nitrogen cycle in times of high waste and insufficient Beneficial bacteria Colony size.
Ph is the level of Alkalinity of the water. 7 is Neutral, 7 is acidic and >7 is basic (alkaline)