Hi Mervyn,
Congratulations on your new Nerites! It’s really good that you were allowed to have them – they are real little helpers. As for them being escapists, I read a few times that they do this when they are not happy with the water conditions they are in. I cannot quite comment on that but can say that they never tried to escape from my tanks – my tanks all have glass covers with quite large cuts out for equipment and I never had them crawling out – they go close to the edge of water and then go back. I never had them trying to escape. If buying them from shops, it is good to ask the staff to pick one for you which you can see moving along the glass or the substrate. Of course, you cannot do this if buying online... But do report back to Kesgrave tropicals if you have a non-active specimen – I would think they should give you a refund.
Hopefully, your tank will be moving in the right direction now. It is just a little patience needed as good changes tend to happen much slower that bad ones in aquariums! Also, this new routine will have to be “fine tuned” as you go to find the optimum for your specific tank – but this is all the fun: to be moving towards optimum. When an optimum is achieved , the routine will become probably less time consuming but in a way a little bit boring because everything will be running fine and there will be no case to employ “little grey cells” (Poirot). This is why many people who had themselves “hooked” onto planted tanks start changing layouts and trying new plants!
With your tap water, I think you need to decrease the amount of fertilizer (lower it to 4 ml). This is a correct thought from you – ideally you should have gone for a “complete” version as plants’ main “food” is carbon, Nitrates, Phosphates and Potassium. Micronutrients which I understand your current fertilizer has are already present in your tap water as it is hard (maybe not all of them in sufficient quantities and not in the easy for plants form but still...). Again – nothing to worry about. You can (and should) still use this fertiliser and it will last you for longer. I understand you are on a budget so we will try to sort you tank out spending only a little bit of money (if any). I would not go down on liquid carbon, though – overdosing it is right as far as I can see (even maybe trying slightly more 4.5 -5 ml perhaps?). I think that the main issue to sort now is the flow distribution in your tank – to make so efficient that all corners and nooks have some water moving. This is the only thing I think you may need to spend some money on at the moment. You have a spray bar which is best for your tank. I am presuming that it is positioned along the side of the tank – am I right? You have a good filter – Eheims are rated very highly, and it is a much better litres per hour is way better than the filter you had. The effect you need to achieve is that the water from the spraybar goes along the length of the tank, hits the opposite side wall, goes down and then flows along the bottom in the opposite direction towards the filter inlet. Of course, pieces of decor and plants will alter/slow down the flow. So, what I am thinking: could you have a look at the side of the tank opposite to where you spraybar is positioned – do you see any movement of plants? If you don’t, that means the power of the flow does to bring it quite to the opposite side wall of your tank. If this is the case, perhaps, it would be better to buy another additional matching spraybar on Ebay, connect it to the one you have and position the new long one along the back wall (the longest one). The filter intake can be positioned on the same wall either corner. This is “fine tuning” and positioning of the spraybar and the intake can be althered until you see and feel that most of the tank has some water movement. This will only require some additional tubing and a spraybar (even second hand). These are the only expenses which I think you could have now. As your tank develops, more “fine tuning” will probably be needed – not necessarily involving any more spending....
P.S. I love your boesemani rainbows - very beautiful fish and suited to your water parameters well!