Problems New Tank

Unfortunately for you there now is a lot of demand for higher lime content rocks and gravel, mostly used by keepers of Rift-Valley fish - the natural water there has a high pH and is also pretty hard too, so shops have every right to be selling them, to answer your question.
Having said that you really should have tried the 'vinegar test' beforehand...but as you're newcomers there is no reason for you to even have considered it. My advice for any newcomer is that the VERY FIRST thing you buy is a good quality Test Kit, and this is not solely my opinion, it really is a MUST.
However, you have done the next best thing by having your local fish suppliers test samples of water for you. Unfortunately in this instance perhaps they were found to be a little 'wanting'...

You have done the right thing by removing both the gravel and Ocean Rocks. My suggestion for now would be to continue your water changing regime, but less per change - but more frequent. This is because your fish will have become acclimatised to the very high pH and sudden drops in acidity can prove to be not in their best interests, you could buy some Peat (I find the pellets to be very good in that they do not release small fibres into the water, which can look unsightly) into a mesh bag and put this into your external filter. The pellets release their acidity more slowly too, but will cause your water to take on a brownish hue which some people dislike and others (myself included) find a more 'natural' appearance.
Should you not like it I am assured that putting carbon into the filter will remove the tanning colour...but beware, carbon does need changing (or removing) after only a little while as it starts to release any 'unpleasantnesses' it has previously removed once its capacity becomes full.

Keep monitoring your pH and once it reaches the same as the top-up water you can remove the peat, then your pH will become stable...but if it starts to drop suddenly then you will have to take evasive action as a pH drop is every bit as dangerous - possibly more so - than high pH!

Let us know how things progress, and by the way, welcome to the Forum.

John

Sorry then, I cannot think of any other suggestions to make - well, not simple ones anyhow.

Are you absolutely certain you have now removed all the offending gravel and rocks? - I don't suppose you have any ornaments?

In theory, if you are replacing water with pH 7 then it must start to come down, I am certain - it's only when you have something in the tank acting as a 'buffer' to bring up the pH that the change would not come about.

I apologise in advance for asking this, but you are certain you are reading the test results properly? Although you only just bought it there could also be the very slightest of chances it might be 'out of date' - but most unlikely.

Are your fish OK? - ie feeding and acting normally? - any fish losses?

I think that as long as the fish are OK then keep up water changes, if you change 10-15% even every day I cannot see how the pH will eventually start to come down.

One last question? - How long have the peat pellets been in your water? I'm wondering if they were in there when both the alkaline gravel and rocks were there whether they might have lost their effectiveness by now.

Other than that I can make no further suggestions - anyone else?

John

Well,
You seem to be getting somewhere now, it's a real shame about the Rams, but I've expressed the opinion before that some of the so-called 'German Rams' actually emanate from the Far East - even though the strain was originally developed in Germany. These are now very delicate (understatement) and often die very soon after being brought to their new homes (our tanks)...on the right towards the top of the page there is a 'search' facility, type "Rams" or "German Rams" and 'go' you'll be amazed at some of the problems people have had with them, and this is only one Forum!!!
You might want to hold off replacing them, a fish of neutral/low pH water, until your conditions have stabilised - at least to the same pH as your source water is.

When the opportunity arises check your ornaments to make sure they aren't broken in a small way, many are made from plastics which ought to be OK anyway but some are made from moulded and sealed plaster - which, if damaged could leach into the water over time, having an adverse effect on the pH. This probably isn't the case, but check just to make sure.

Let's hope your problems are gradually coming to an end.

Keep up the water changes!

John