Gh To Suit Most Plants

[KPD]

Hi all
I'm having trouble judging exactly what Gh will suit most plants. I'm fairly new to looking after plants properly. I've recently added CO2 injection and I add NPK plus minerals.

However,....my GH is very high at around 20....which I think is on the high side even for many plants that are suggested as tollerating hard water. I already have an RO unit and am flexible on the GH I aim for, but don't want to over do it and compromise my buffering capacity. Due to the size of the tank (720 litres, but about 620 after diplacement of gravel and rocks, etc) I am limited to no more than 16% to 24% water changes per week.

Currently, despite the nutients and CO2, there are some plants that don't do well and some that do OK, and just one or two that do very well. I suspect that part of this si down to the GH.

I was just hoping for a very general steer or what would be a good GH to aim for to suit most plants? Ones I have that are hanging on but not doing well include Lilaeopsis brasiliensis and Aponogeton ulvaceous. The amazon sword is also producng rather transparent weak looking new leaves. Plants that are doing well include Echinodorus Red Flame (sorry, don't know the latin name).

Thanks for any advice
Kev

 

[Colin_T]

most true aquatic plants will grow in hard or soft water. I have had ambulia growing in water with over 400ppm GH. Good lighting and iron fertilser help as does the CO2. I wouldn't worry too much about the hardness. Instead look at the plants you have. Chances are some of them are not true aquatics and will never do well under water.

 

[Themuleous]

Plants will adapt to most water conditions, so I wouldn't worry to much.

Sam