using tap water?

[barjam]

The question I have is if you were given two reef tanks that were exactly the same... one using the cheap ebay filter and one using a top of the $3000 56 filter RODI would a person notice any differences in the two aquariums? Is that 2% more TDS going to matter at all? Assuming the husbandry of the two tanks were identical and good water changes were happening the levels aren't going to build to any great degree.

On the other hand, there isn't a lot of difference between $100 and $200 when the item in question is going to last you 5+ years.

*shrug*

 

[AZDesertRat]

The answer is an unqualified yes. I have already answered this same exact question either earlier in this thread or in another similar one. Many contaminants in drinking water cumulative meaning they build up and do not go away. Some get into the rock and sand and corals structure and are not removed with water changes. Its best to not add them to the aquarium at all hence the RO/DI system.

 

[barjam]

I don't mean on paper, I mean in practice. What differences would one expect to see? Given the two systems in question are there examples of a coral that could be kept in one tank vs the other?

Considering the salt we use:

http://www.reefkeeping.com/issues/2003-03/rs/feature/index.php

It looks to me like we take everything out only to add a bunch back in again. It looks like salt I use has far, far more impurities (aka trace elements) than my local tap water.

I am a newbie and I plan to get a nicer RO/DI when the time comes (you tend to get what you pay for) but I just don't see how that 1% would really make any sort of difference on a normal hobby reef tank.

 

[xxxjwxxx]

<a href=showthread.php?s=&postid=8050427#post8050427 target=_blank>Originally posted</a> by barjam
I don't mean on paper, I mean in practice. What differences would one expect to see? Given the two systems in question are there examples of a coral that could be kept in one tank vs the other?

Considering the salt we use:

http://www.reefkeeping.com/issues/2003-03/rs/feature/index.php

It looks to me like we take everything out only to add a bunch back in again. It looks like salt I use has far, far more impurities (aka trace elements) than my local tap water.

I am a newbie and I plan to get a nicer RO/DI when the time comes (you tend to get what you pay for) but I just don't see how that 1% would really make any sort of difference on a normal hobby reef tank.

It looks like we all wasted our money on either an e-bay system or an awesome system. Time to get our own 200g buckets and fill up on catalina water.

 

[AZDesertRat]

A 1% difference in membrane efficiency between 97% and 98% means double the contaminates going in to your tank. It is a big difference. A 2% difference in membrane efficiency means either double or 1/2 the life of a DI filter. Both are big deals and not only affect livestock but $$ spent on replacements.

Remember the EPA sets standards for human drinking water which is very different from what our corals need. Things we can consume wil kill a coral.

 

[barjam]

That is actually the primary reason I plan to get a nicer system. I figure I will eventually make back the cost on DI replacements.