I thought I was the only one who didn't know this as a newbie....
I had very hard water for my FW
tank...and I was told..."Just get a RO
Filter". To me...and any newbie..since you have bought you HOB
Filter, or Canister Filter (and probably a Diatomic filter by now to fight the algae brough on by your tap water)...you would assume that this "filter" would also be for the aquarium.
...But it is NOT for the tank...think of it as a filter for your TAP water. Then the nice clean "TAP" water...now RO
Water... gets added to the tank...and in my case with a bucket.
Most people use RO
water for Saltwater Aquariums...they use the RO
ONLY and add their salt. A few people use it who have FW
tanks to "adjust their Tap water". In my case...by pH was too high at 7.8...so I used 1/2 Tap and 1/2 RO
to get the pH to 7.5 or so. Now I use all Tap water for my FW
as the water has great KH
and I used a pressurized CO2
system to keep my pH at 6.8...and all Alage is kept at bay.
90 Gallon Fresh Water Planted w/ CO2
7 Brilliant Rasbora, 6 Harlequin Rasboras, 3 Dwarf Neon Rainbows, 1 Red Tailed Shark, 2 American Flag Fish, 4 Skunk Botia Loaches
40 Gallon Breeder Salt Water: 4 inch DSB
(2/3 Agaramax & 1/3 Sea Flor), Bak Pak 2R Skimmer w/ BBX, 2 x JBJ PHs, Coralife Lunar Aqualight (2x96w), 30lb Base Rock and 40lbs of Live Rock.
Inhabitants: Purple Firefish, Pygmy Angel, Lawmower Blenny, 2 Cleaner Shrimp, 1 Peppermint Shrimp, Pistol Shrimp(HH), 1 Emerald Crabs, 3 Porcelin Crabs(HH), varying amounts and varieties of hermit and snails.
3 Gallon Eclipse:
1 Goldfish (won free at a fair...cost $50 in equipment)