pH shock?

I have a 29 gallon tank that is fishless cycling right now (battling high nitrite readings at the moment). When I first started out, my tap pH was around 7.4, and my tank pH stayed around the same. However, I tested my KH and found out that it only took 1 drop to change it to yellow. So I added a media bag of crushed coral to my filter (HOB). A few weeks later, my tank KH is now at 3 drops, but my pH is 8.4. My two concerns are that:
1. Will the difference between my tank pH (8.4) and tap pH (7.4) cause shock when I do water changes?
2. I plan on getting GBRs. Will this pH be too high? I understand that normally fish are fine when you slowly acclimate them because they are normally captive bred in all types of pH, but I also have heard that Rams are more sensitive to water conditions.

I am in a conundrum because without the coral, my KH will be lower which could eventually lead to pH shock...but with the coral the aquarium pH is much higher than my tap pH.

: (

 

I can't speak to the fish questions, but regarding the pH, if it will go with your décor, add some driftwood into the tank. The tannins it releases will help to naturally lower the pH a little bit. My tap is 7.8 with 1-2 drops KH I also use crushed coral to help with the KH. One tank I have it for the full substrate, the other I have half coral and half rocks (so lots of coral in both tanks). The coral alone raises my pH to about 8.2, but with driftwood in both tanks, the pH stays at a completely stable 7.8.

 

Cool thanks! Should I boil driftwood prior to putting it in the tank

 

Typically yes, you want to boil it first to remove a bulk of the tannins, unless you want tea colored water If you are using something from nature, then you would want to boil it to get out anything that may be harmful as well.

 

In addition you shouldn't have ph shock issues if you keep the net ph change under .5. E.G. if tank ph is 8.4 and tap ph is 7.4, the the maximum water change you'd want to do at once would be 50%.

 

Tannins will lower your KH, which is not what you want. Cycling uses up KH more quickly than your fish will, so you could add a small amount of Potassium bicarbonate or Sodium bicarbonate to keep the KH up while you're cycling. When you have fish, a smaller amount of crushed coral should be enough, especially if the tank will not be heavily stocked. If you could also store your water change water in a container with a little spare filter containing crushed coral, that would help too...

 

Awesome thanks all! I'm finally cycled!!!! So I will see how things develop