Just checking, as of course all my lfs' have a ph of 7.8-8.0, and with the usual losses, they don't seem to have too much of a problem. I'm still keeping an eye on ph regularly, and considering certain options of reducing it as a long term basis, though of course I know this is difficult, my larger future tanks will be based around fish that are more suited to this ph level.

I understand about exponential rates and levels of ph, i.e. acidic and alkaline.

The thing with your LFS is that they get the fish in do a quick water aclimatisation, quarantine(Most of the time), and then sell out all within the space of about a week, 2 at most. So their fish are not in their tanks that long. The fish may have come from a totally different area where the water is a completely different PH. So the fact that they appear to be OK is a bit of a false representation. Your fish on the other hand are in your water for a lot longer and so any problems are going to be more prominent and will appear within a short space of time. The problems have more than likely all ready started whilst in the fish tanks at the LFS. But as is often mentioned here, the LFS will tell you what you want to hear and that is that all fish they sell do well in their tanks with hardwater as they are acclimatised. They want to take your money. Fish have taken 100,000's of years evolving to the point where they thrive in water of a given PH and hardness etc. This will not change in a few hours of topping up with your own water prior to adding to the tank. PH is a very important factor in the difference between a fish surving or a fish thriving. Softwater fish require softwater and a lower than 7 PH, hardwater fish need hardwater with a higher than 7 PH. It takes a lot of experience and experimenting to be able to lower the PH of water in a hardwater area and keep it constant, it takes a lot of hard work and patience. It is easy getting the PH down but keeping it down and stable is the hardest part.

Especially bringng it down from such a high level of around 8.0, this is why RO water is essential. You can even have problems if you keep the PH at 8.0, when it comes to the decor. If you buy rock or substrate that is alkaline this could push the ph up above 9 and this is no go territory for any fish, bar a very few specialised species.

As an aside - the stones you've got in the tank look quite large. Larger stones make it easier for bits of uneaten food and general grot to settle between them and it's not so easy to clean around larger stones. I can't imagine you will find it easy to use a syphon gravel vac as you don't really have enough water to be able to remove enough to clean the substrate while you syphon. The small battery powered one I've got needs a certain depth to be able to operate, I'm not sure a tank of 17 litres would be deep enough. I had 'fun' getting it to work in the 20 litre tank my late veiltail was given to me in

I can't decide what you mean by 'deep clean' - can you clarify?

It is a local breeder (have been there myself), rather than import, and the whole of my area is of quite a high ph, just to note. Like I said, I'm still trying to figure out the best way to have a long term, stable ph, at least for my first two tanks, next ones will be stocked with fish that are suited to the ph, which I've already stated.

True, the gravel is quite large, but the two sizes i had available, I thought this size was best. I use a piece of air tube to syphon, rather than an electric vacuum as my other tank has aquaria sand, waiting to do my first water change (only been a day).

The deep clean was suggested by a member on betta paradise because my betta died, and it was just to ensure that there were was nothing in the tank that had pushed the ph up, etc. I removed all of the sand and threw it away, rinsed it down to get rid of any left over grains and then used hot water (not enough to crack the glass) with a solution of 16 parts bleach to 1 part water. Rinsed again with cold water after a few hours (the tank was not left full with the solution), rinsed a few times again, and then wiped down and dried. Left for a few days before putting the washed gravel into the tank and setting up.

16 parts bleach to 1 part water? That is almost pure bleach, dont you mean the other way round? You should never ever put anything like bleach anywhere near a fish tank or anything that will go in it. That is just basic fish keeping protocol. Vinegar is about the limit of corrosives that should get in the tank. No matter how well you rinse the tank, do you really want to take the chance of leaving the smallest residue behind...?

Local breeder or not the water will still have to be right for the fish to breed. If you have softwater fish they will still need softwater conditions to breed and for the eggs to hatch and for the fry to survive to strong healthy fish. I breed fish here and mine are all bred under the conditions nature intended. I would go to your local breeder and ask what conditions he breeds his fish under.