Originally Posted by Fixed
Anyone know a good source of info on procedures and recipes for making buffered water for top offs and replacement salt water? How long to "age," those sorts of things? I have my RO setup going and have 50 gallons of water sitting there, but I'm a little unsure of myself now. Can you do things like make a concentrated jug of salt water to raise salinity as needed, for example? Suggestions? Thanks.
For top-offs just use ro/di water without any salt. You generally don't need to add buffers unless you're specifically trying to raise the alkalinity of your water (i.e. its resistance to fluctuations in ph). And if you're going to do that, you need to do so carefully and you need to carefully test your alkalinity and/or kh along the way. Generally, just top off with regular fresh ro/di water
As to raising salinity, don't make a concentrated jug of saltwater. That will raise salinity too quickly. Instead, if your salinity is low, just do an occasional top off with regular mixed saltwater. Over time (which is the best way) it will increase your salinity. You don't want to raise it fast. Very hard on your critters.
On aging, I've heard people suggest letting ro/di water age for a day or two before use, though I don't usually do that for top offs.
However, you really should let saltwater age at least a couple days before using it in your water changes, if possible. I think most of us 'cheat' in emergencies from time to time, but it's best if the water has been allowed to mix for a few days (throw a heater and powerhead in the container where you mix your saltwater) before use in the tank.
Why is this aging necessary? I can say that in my experience I get surprising fluctuations in the salinity of newly mixed saltwater. I guess sometimes the salt crystals just haven't completely dissolved or whatever. I can also say that newly mixed saltwater is not very clear, which suggests that the minerals are not completely dissolved...can't be good for your fish.
Hope that's helpful.
