Whole-house Water Filter Technologies?

[Tres]

I've been looking into installing a whole-house water filter/softener-conditioner, to provide healthier water for family use and to eliminate limescale. Does anyone know if the following filtration technology are suitable/helpful/dangerous as well for aquarium use?

TAC (Template assisted crystallization) to eliminate limescale caused by hardness in tapwater - http://www.purewaterproducts.com/art...rystallization
This produces nano-crystals of calcium carbonate, which I'm not sure how these might affect fish and plants compared to regular hardness??

[Frankr409]

For whatever reason that link is not working, at any rate, if it exchanges salt to reduce hardness, this wouldn't be a good option for your fish.

[Tres]

Here is the link again, in different format, (or are we not allowed to include links?):
http://tinyurl.com/m75guuo
It's not an ion-exchange water softener that replaces hardness with sodium or potassium in any case.

Has anyone used KDF filter media either by the way? http://www.thewaterexchange.net/what_s_kdf.html
Apparently it uses copper and zinc media, and, "only a slight amount will be left behind (<0.05 mg/l copper and only 0.46 mg/l zinc0". Are those levels too high for discus however?

[Tres]

Goal - To remove; pathogens, numerous chemicals, pesticides, fluoride, nitrates, heavy metals, copper, lead, and significantly reduce limescale.

Cartridge 1: 5 micron sediment filter (Remove sediment, lengthen the life of other cartridges - optional) (Source water median turbidity is 0.07 FTU)[/FONT]

Cartridge 2: 1 micron sediment filter (Remove sediment, lengthen the life of other cartridges)

Cartridge 3: TAC (Template Assisted Crystallisation: to reduce limescale, including in KDF media)

Cartridge 4: Nitrate Reduction Cartridge: (Pozzani NR600: £13.98), (strong base anion resin or nitrate selective resin CQ-N250) (26 mg/l median Nitrates in Source Water - 10 mg/l max recommended)

Cartridge 5: KDF-55 redox treatment: remove up to 99% of water-soluble lead, mercury, nickel, chromium, and other dissolved metals/ kill algae and fungi, control bacteria growth, and remove chlorine, pesticides, organic matter, rust, unpleasant taste and odour, hydrogen sulfide, iron, lead,nickel, chromium, cadmium, calcium, aluminium, mercury, arsenic, and other organic compounds

Cartridge 6: Activated Coconut Carbon
(Activated carbon filters remove/reduce many volatile organic chemicals (VOC), pesticides and herbicides, as well as chlorine, benzene, trihalomethane (THM) compounds, radon, solvents, and hundreds of other man-made chemicals found in tap water. Some activated carbon filters are moderately effective at removing some, but not all, heavy metals. Catalytic carbon filters are effective at removing chloramine and hydrogen sulfide.
Carbon filters are NOT generally successful at removing dissolved inorganic contaminants or metals such as minerals/salts (hardness or scale-causing contaminants), antimony, arsenic, asbestos, barium, beryllium, cadmium, chromium, copper, fluoride, mercury, nickel, nitrates/nitrites, selenium, sulfate, thallium, and certain radio nuclides. Removing these contaminants requires either a reverse osmosis water filter system or a distiller (some can also be removed by KDF-55).

Cartridge 7: Bone char carbon by Brimac in Scotland/Promolife to remove remaining flouride, zinc, and copper. (0.14 mg/l fluoride in source water, 0.05 mg/l copper and only 0.46 mg/l zinc likely resulting from KDF filter media)

(Or GFO/GFH Granular Ferrous Oxide Hydroxide for removal of residual zinc and copper)

With a multi-stage filter such as this, I'm just not quite sure how often the cartridges should be changed in comparison to standard guidelines however...