Filling a 120 Gal Tank

[Criminal_Colt]

Hi,

Look this might sound like a very stupid question but should I use R/O water from my LFS to fill my tank for cycling or will tap water be ok?

Its going to come to 500liters and retails at $5 for 25Liters. So it will cost me $100. Thats in aussie dollars.

So, do I really need to do this or can I skimp on this. The reason I ask is that this is just for my cycling NOT for keeping fish. I mean, obviously there will be fish in there in 2 weeks or more likely a month but initially just the water and substrate. So, will the water clean itself up? Or am I ensuring a quick death for my fish?

The tank is fish only with live rock. No corals.

The water I would use would be dechlorinated tap water.

Colt

 

[acefred]

I don't know the answer but you will be wanting RO water anyway why don't you buy an RO unit and then you will have your own sorce for ever......

 

[OrionGirl]

What's in your tapwater? Look at nitrates, phosphates, and metals. Using RO--for initial fill, all water changes, and topoff--is preferred, simply because it reduces what you're introducing to the tank. The cast majority of these potential contaminates will still be there a week form now, and a month form now, and so on. If you do every water change with RO water, the initially introduced contaminants will still be there for quite a while (do the math, assuming a 25% water change on 100 gallons of water: down to 75 gallon on the first change. Then down to ~67 gallon on the second. Then down to ~59 on the third...You can see that you actually removing very little of the original water with subsequent water changes.) Since these contaminants won't evaporate out, topoff doesn't contribute to their dilution, only water changes will actually pull them out of the tank. Starting with RO, you can save yourself the headache of later needing to get rid of something you introduced.

Probably cheaper to just buy your own RO unit, though--both for initial fill, changes, and topoff. Certainly less of a risk than needing water and having the store closed!

 

[Criminal_Colt]

Yeah i would agree spending the extra and getting a unit for between $200-$300 does seem like a good idea but I'm very annoyed about the amount of water it wastes. Here in Sydney we are having a major water crisis (we cant touch a hose or we get fined) so I would feel kind of guilty about using an R/O filter. Apart from that its a cost I hadn't anticipated.

HOWEVER:

If I do a 10% water change once a week (recommended?) that will cost me $40 for SW from my LFS. If I buy the RO unit the salt will cost me $20 a month again for 10% every week. So in a year I would save $240 plus I would save the initial $100 so all in all $340.

I will find out how much a liter of water costs from our water board and take that into account.

I'll have to think about this.

Hmmmmm *Goes into deep thought*

Colt

 

[Criminal_Colt]

Orion how would you suggest I check for contaminates in my water? I cant find any details from other places.

Exactly how risky is it to use plain tap water?

Colt

 

[acefred]

Just throwing this out for the experts to answer, Colt lives in Sydney...Therfore right by a great ocean.............Can he just use this water? It would be salt and must have all or most of the needed nutients..............

 

[OrionGirl]

Contact your water utility and ask for a report--I'm guessing they will have it available. I know it is a requirement here in the States, so just a guess. I agree with RO waste water being bad--BUT, you don't have to dump it down the drain. The water is great for plants, great for laundry, great for cleaning the counter. You can have it go into a storage container and use it for other things. We had water restrictions here as well, and I used all my 'change' water from the FW tanks to keep my plants happy--the RO 'waste' water would be fine for this.

For the risks: algae blooms is the big issue. Nitrates and phosphates in the water can feed algae blooms. While this is not a lethal problem, it's an aesthetics issue which has caused many people to leave the hobby in frustration--once the algae starts, it can be hard to get rid of it.

Using ocean water is possible. You have to be able to collect from a few miles off shore to reduce the odds of toxins, which concentrate closer to the shore. There's aso the risk of importing diseases--most who use ocean water age it in tubs for 10+ days in the dark to kill off anything that may be in there. Which, of course, means you lose the potentially beneficial life, and possible have ammonia/nitrates from their deaths that you're now adding to your tank. So while it's an option, it's not really the best one, IMO. Of course, I'm 1,500 miles from any ocean, so maybe that's just sour grapes.