That looks like it makes distilled water which like RO water is pure water with nothing dissolved in it - though why it would also need carbon as well I have no idea. That water can be used instead of RO.
The downside to the rocks is that they would probably dissolve slowly, and when you do a water change adding distilled water there will be a time lag before they dissolve to give the same level of minerals as before the water change. With powders, they are added to the new water before it goes in the tank, and you would add exactly the same amount every time to keep the level in the water constant.
It is always better to make up the water before it goes in the tank as fluctuating water conditions are not good for fish.
With a 5 gallon tank, you would need to change about 2.5 gallons a week, provided the tank was cycled before getting any fish or shrimps. Doing a fish-in cycle needs daily water changes.
Or, use un-purified tap water, add dechlorinator and keep a dwarf puffer. They are fine in hard water and 5 gallons is big enough for one.
www.seriouslyfish.com
The downside to the rocks is that they would probably dissolve slowly, and when you do a water change adding distilled water there will be a time lag before they dissolve to give the same level of minerals as before the water change. With powders, they are added to the new water before it goes in the tank, and you would add exactly the same amount every time to keep the level in the water constant.
It is always better to make up the water before it goes in the tank as fluctuating water conditions are not good for fish.
With a 5 gallon tank, you would need to change about 2.5 gallons a week, provided the tank was cycled before getting any fish or shrimps. Doing a fish-in cycle needs daily water changes.
Or, use un-purified tap water, add dechlorinator and keep a dwarf puffer. They are fine in hard water and 5 gallons is big enough for one.
Carinotetraodon travancoricus (Dwarf Puffer) — Seriously Fish
www.seriouslyfish.com
