Soft Water Conditions

I don't know much about plants having only a few species of 'easy' plants but I do know that soft water isn't low in just calcium & magnesium - it is low in everything. Fertilisers are important in soft water as there are very few minerals in soft water.

The fertiliser that I've seen recommended as containing all the minerals needed by plants is Seachem Flourish, the one with nothing else in the name. Apparently, most other plant fertilisers are lacking one mineral or even a couple of them. Flourish doesn't contain nitrate or phosphate as those come in different Seachem products - and nitrate is made by fish and there is phosphate in fish food so a well stocked tank should provide enough of those.
Andy will now tell me that he is already using Seachem Flourish 

Another thing I do know is that algae grows when something is not in balance with fertiliser, light duration/wavelength and CO₂. People who do know about plants talk about trying to establish which of those is out of balance and correcting it.


Because my main tank is not heavily planted and I have only slow growing plants, I don't use the full dose of Flourish. I need to add some now as I did a water change yesterday and have got the bottle out of the fridge. The dose on the bottle is 5 ml per 250 litres once or twice a week. For 180 litres I should use 3.6 ml but I use just 2 ml once a week. But I do have that algae that looks like black fur on the plants in full light. I don't get it on the plants under the floating plants so the cause of mine is probably light.

Try www.barrreport.com, id be interested to know what you find out 

I have Tufa/limestone rock in the tank on a permanent basis - although KH and GH do fall post water change, it does keep them up at about 2.5 and 4.5 respectively from about mid-end of week from a 'natural'/tap water level almost as soft as yours.