Ocean Rock Ph

[SensesFail]

I had a post recently about this but does anyone know if removing the oceon rock from my tank and using slate instead will this drop my Ph drastically? My tank Ph is 8.6 at the moment and I can't off hand remember my Ph from the tap but I'll try and find this out. Will removing it drop it enough to really affect my fish? And what's the best way of changing if it can even be done? Fancy a change and am currently going to invest in a 50L sump to work along side my cannister

The picture to the amount of oceon rock is in the link below and I would be keeping the coral sand etc.

 

[Davo86]

Coral sand has the same effect so will keep the water buffered, and therefore removing the ocean rock should have little effect straight away but may drop as and when you change the water

Coral sand has the same effect so will keep the water buffered, and therefore removing the ocean rock should have little effect straight away but may drop as and when you change the water

 

[SensesFail]

Coral sand has the same effect so will keep the water buffered, and therefore removing the ocean rock should have little effect straight away but may drop as and when you change the water

Coral sand has the same effect so will keep the water buffered, and therefore removing the ocean rock should have little effect straight away but may drop as and when you change the water

From what I remember my tap water is 7.4 I do 2 20L water changes a week on my 200L tank would it be ok for the fish with the levels possibly dropping gradually? Or would I be better off trying to add other things to the water to keep it where it is after removing the rocks? My 50L sump will be getting done in 3 weeks when it's ready and I was thinking of changing this before?

Really want a slate effect as apposed to oceon fancy a change