Tap water for winter?

[Apwhite]

Like many, I use ro water for my tank which is a 10g with only a clownfish in it as of right now. Where I live, it gets pretty cold in the winter and I’m concerned that there will be issues with my pipes if I use my RO system. I know that using tap water normally isn’t the best idea for a saltwater tank, but will it be acceptable to use for the next couple of months until it gets warm again?
P.s. there is not an option for me to buy water from lfs

 

[connorlindeman]

As long as you properly treat it, it should be fine. I am not an expert with saltwater tanks. Maybe someone more knowledgeable can chime in.

 

[StevenF]

were is your RO system located? It is in a separate unheated building such as a garage yes it could freeze. If is in your home it should be OK unless you loose power for several days. Since your tank is small the easiest thing to do is to store water in large plastic container. With the container sealed the RO chemistry will not change and it can restored for months until need. Even if the stored RO water freezes it is still good.

You could also add ocean salt to the correct concentration to the RO water.Salt water freezes at a lower temperature than fresh water. then you could just do a regular water change (Remove some of the old water and refill to the correct level).

If for some reason your RO system freezes you would have to replace all of the filters. So make sure you have a spare set of filters on hand. If you suddenly loose power and expect the RO wysten would freeze before power is restored , shut of the supply to the RO system and removes as much water ass possible from the system.

 

[Donya]

I assume the issue must be that it's outdoors or otherwise somehow unheated like StevenF mentioned. Can you switch to a sink connector and run it out of a bathroom? I have a small unit that is connected to my sink and is slow, but slow is way better than dumping phosphates and/or carbonates into your system every time you top up. You can end up suffering algal/cyano blooms for months from even short-term tap usage depending on how bad the tap water is for certain things, and that can be true even if you treat it as you would for a fw tank and run chemical media to try to mitigate the unwated phosphates/etc. Salt mixes can also have trouble dissolving due to carbonates in the water, so if you have a high KH then RO is pretty important.

 

[jaylach]

I have had both fresh and marine tanks in the past and have never used anything other than tap water without issue. I just check the parameters of the tap water and select fish that fit the range.