One the basic laws of keeping a saltwater tank is to only use water from an RO/DI system for your tank. RO/DI water is very, very clean, so by using it, you won’t be introducing bad things into your system such as silicates, heavy metals and chorine that can cause a major of problems in your tank.
(If you are interested in learning the chemistry behind how an RO/DI unit works, read this article)
RO/DI water is usually available at local fish stores so a lot of saltwater tank owners ask,”Do I need my own unit when I can just buy it at the fish store?”
For all the tank personalities, my answer is always, “YES!” and here’s why:
1. Its a matter of having insurance.
If anything ever goes wrong with your tank such as it starts leaking, or you need to do a large water change, by having your own RO/DI unit, you’ll have the piece of mind that you can make all the water you need, when you need it. If you didn’t have a RO/DI unit, then you’d either have to store large amounts of water in jugs which takes up a lot of space and are heavy and not fun to move around. And, if you didn’t have your own unit, then you’d have to bank on the fact that either your buddy who has a RO/DI unit would want to take your call when you call them AND that they’d be willing to have you come over at any moment to pickup more water. Oh yeah, and you’d have to rely on the fact that they actually had enough water on hand to meet your needs at the time. Murphy’s Law would apply here that chances are when you need the RO/DI water, your buddy would have just used up his supply so you’d be fresh out of luck.
Also, I’ve yet to see a local fish store that is open 24/7 so if you needed the water when are closed (Murphy’s Law again), well, I hope you (and your tank) can survive the wait.
There is a certain peace of mind knowing that if anything goes wrong in your tank, all the water you need is within your reach.
2. Its actually cheaper in the long run
Most local fish stores sell RO/DI for 25 cents a gallon which is pretty darn cheap. But what most tank owners don’t think about is the amount of time they spend driving to the local fish store, filling up their jugs, loading their jugs (did I mention they are heavy?), driving back home and then unloading your jugs. And unless you have a set routine to get more water from the fish store, chances are you’d run out when the store is closed.
Doesn’t sound like a big deal to you? Well here’s where you really save money:
By not going to the local fish store, you aren’t walking by all the pretty display tanks and being tempted to buy that fish or coral that is just calling your name! (Remember those puppy stores in the malls back in the 80’s? There is a reason they put them by the front entrance!)
I actually think local fish stores should make their RO/DI water 10 cents so people couldn’t resist coming into the store. More people in the store = more sales. How many people do you know who go into the fish store to buy one item and come out carrying 3 or 4?
When you put a RO/DI unit in your house, you remove temptation and retain money.
3. You get to maintain control
When you own your own RO/DI unit, you’ll know exactly how long ago the filters were changed and how clean the water coming out of it really is. No more counting on someone else to keep up their system, you’ll know when its time to change the filters and how clean the water is coming out of the system.
Even if you are a tank dabbler, you can pickup a 35 gallon/day unit that doesn’t take up a lot of room and will keep you from spending a lot of time dealing with your tank.
A good RO/DI unit, isn’t cheap, but they more than pay for themselves in less tank headaches and having everything you need on hand in an emergency.Browse the Store! Questions?