Tap water ok?

[havefun]

I am going to be setting up a 75 gal FO tank. In the past I have had FW tanks and just filled several milk jugs with tap water and left them sit for a week or so before using them for water changes. Can I do the same with SW? Obviously I will need something larger than milk jugs but will leaving the water sit for a week remove the harmful chemicals? Or, should I just plan on getting an RO/DI device (remember this is for fish only)?

[IfoundNemo]

I recommend using RO/DI over tab water to set up your tank. You will end up with more problems using tab water even in FO SW system, because it has unwanted chemicals, and nutrients which leads to outbreak of brown algae.

[Bearfan]

I recommend RO/DI too.

[havefun]

Thanks, thats what I thought would be the response.
How much should I expect to pay for a device/filter to create the RO/DI water?

[Phyl]

What is the TDS of your tap water? Phosphates? Nitrates? If you have low TDS and 0 Phosphates and Nitrates then you're going to be in much better shape using tap water than someone else. Because tap water varies so greatly from area to area, city v. well it is really hard to say what your tap water is going to present to your tank in the way of challenges.

We started our tank (in October) with tap and have just recently switched the water over to RO/DI. Really for no other reason than that we should be using RO/DI water, the tank is in perfect shape with no algae to speak of. The unit we got was from eBay. It is from FilterDirect and ran us around 90$ for 100g a day (which, I have to tell you, looks incredibly slow when you're watching it pour)!

Certainly RO/DI is the way to go if you can and in this hobby the 100$ is well worth the peace of mind that nothing that I'm not intentionally putting into my tank is getting into my tank.

[moejoephd]

Use the RO water if you can. What i did 2 cheat a bit was initially filled the tank (100g) with tap water, and i do tops offs and water changes with RO water. Worked for me, but i would look into it more.

[pmac0816]

I run a 75 gal tank that was fo for awhile. I am using tap water from my well with few problems until I added LR to the tank. I am constantly fighting brown algae and increased water changes. RO/DI filter is now on order.