Re: Aquatic Plants Digest V6 #175

[Michael Eckardt <mike at odg_com>]

     * From: "pieter cool" <pieter_cool at esat.kuleuven.ac.be>
>
>.....Might there be any problems with using very hard (Kh and Gh
>about 20 ) tapwater for a planted aquarium?
>For the moment I'm using RO water mixed with tapwater to get a
>hardness of 10 Kh. Because this is a lot of work I would like to
>skip the RO water.
>One of the plants in my thank that I think migth not be so happy
>with this hard water is hemianthus micranthemoides. Another one is
>cryptocoryne pontederifolia.
>Am I right about this or not?
>Are there any other bad consequences like a higher pH (above 7 )?

There is this myth that planted tanks require soft water. For years, I have 
been running
a number of planted tanks on very hard water - I stopped counting drops 
after 25 degrees
kH and gH. Local fish enthusiasts in my area tend to go for rift lake fish 
because of it.

Hard water has many advantages over soft water:
- very stable pH - i.e. no pH crashes if CO2 dosing is off.
- many nutrients, mainly Mg and Ca, are available and don't need to be 
supplied separately
- no messing with peat, RO systems, water mixing
- most plants do much better in hard water than in soft water - sure they 
can handle soft water, but don't require it

Yes, there are _some_ plants that require soft water - the same way _some_ 
plants require ultra acidic substrate conditions, but I have not found too 
many of them in the hobby. YMMV.

Both Hemianthus micranthemoides. and C. pontederifolia have done well for 
me in hard water.

Bad consequences for pH > 7 only if the tank is really dirty and way 
over-stocked with critters due to ammonia (or is it ammonium - I can't for 
the life of me remember).  No problems in a well managed tank.
I say - go for it!


Michael Eckardt