RO/DI question

[reedman]

I am lucky enough to have very good water straight out of the tap. I still run it through the RO/DI before it goes into the tank. I am thinking of just removing the DI resin all together once it is exhausted. I don't see it doing much for me at this point. Educate me if I am missing something here. I am guessing it is pretty well gone at this point anyway and my TDS is still 0 coming out of the output.

-Reed

 

[ReefJunkie]

Here is a good link that will explain more about RO and RO/DI. http://ozreef.org/faq/starting_out/what_is_ro-di.html
Good luck.

 

[reedman]

so it sounds (based on that little snippet) like I would be better served to just use the Di instead of the RO....strange. Will have to research some more

 

[ReefJunkie]

Actually you can't have DI without RO as I understand it. DI is actually an added process after RO not of itself. Hope that made sense.

 

[reedman]

Hmmmmmmm.....strange.

New question. How do you measure (measure being the key word) the effectiveness of the DI?

And thanks for the insight Richard...appreciate it.

 

[ReefJunkie]

Now you getting way over my head but I have done some reading up on RO/DI. I was wondering at a time back the same as you. Here's another link on DI. http://www.tgipure.com/entry/DI.html Basically, I just decided it was in my best interests to stay with both. Can't base any real claim to it, just figured if it works why change it.

 

[Darthv247]

well, with just ro you should be able to remove 99% of the impurities in the water. add a di resin and you should remove 99.9 % of the impurities. so its really only an extra 1 % or so. if your water is really clean going in to the unit then its even less effective because there is less to purify but it should last longer in that case. you washington folk are lucky to really not even need di period. just an ro should be fine but people seem to like to go the extra mile for their corals

 

[reedman]

well, with just ro you should be able to remove 99% of the impurities in the water. add a di resin and you should remove 99.9 % of the impurities. so its really only an extra 1 % or so. if your water is really clean going in to the unit then its even less effective because there is less to purify but it should last longer in that case. you washington folk are lucky to really not even need di period. just an ro should be fine but people seem to like to go the extra mile for their corals

This is kind of what I was thinking. I was reading the Reefkeeping article on RO/DI and it seemed to echo this. I think I might just remove the DI resin and monitor the TDS for a while to see what happens.

And yes, we are lucky up here...though we make up for it in the taxes our fine government leaders impose (not to mention the lack warm diving ).

 

[Darthv247]

true enough hehe. i had great water when i lived in Minnasota but yeah the taxes werent worth it lol. think they are the highest taxxed state now or at least top 4.

no state income tax in florida

 

[treehugger]

i use this guy here http://www.custompure.com/Merchant2...TWS&Product_Code=10-MB618&Category_Code=CP101 for my water purification. The beauty of this system is you can hook it up to the hose and just blast water through it with 0tds and no waste water. The people over at custom pure can fill you in on all the details of the systems and the various ones that they have (they're like a block away from ARSA) I rent my unit from them since I can't afford the $500 up front. You get about 1100g before it needs to be recharged the the recharges run about $130.

 

[reedman]

Interesting Jeff. Look like they are just running carbon, sediment and a large volume DI filter. More things to contemplate.

 

[braddo]

I'll have to give custom pure a call. I was just trying to figure out how to best fill up a new tank without using striaght tap water or lugging tons of buckets back and forth.

 

[treehugger]

I've been using this type of unit for 8 months now and have had no problems with water quality. I was using RO/DI but got tired of the wate water the lag time to fill large amounts and the hassle of replacing multiple filters on the system. The other nice thing is they reuse the di resin after they "recharge/clean" it at their facility.

 

[DonW]

Carbon alone will not create 0 tds and ro alone will not remove 99% of impurities and yes you can run di alone. Di systems are called kati ani and work very well but can get expensive. Most good ro membranes will remove about 90 to 92% of the impurities if conditions are absolutly perfect 96%. If you connect your tds meter before and after your membrane. You should see somewhere around 90 to 95 percent tds decrease. If your seeing more than that your tds meter is off. If your seeing less than 90% it may be getting close to time for a new membrane or at least recalibrating of the tds meter.

Don

 

[reedman]

Don,

Thanks for the info. I guess I wonder about the measure of the drop from before to after the filter as a measure of effectiveness. If you input very clean water (humor me) then you would not see a large drop, but the filter would still be very effective.

For our water in Lynnwood I believe the input water is under 100 ppm TDS so it doesn't take much to bring it down to 0-2 ppm. Just hate to put money into a filter that isn't doing much for me (ala the DI part of my RO/DI). I have no intention of removing the RO at this point. Though it would be nice to reduce/eliminate the waste water. For now it will water the plants.

 

[DonW]

If your input is 100 the you should have at very least 4 remaining if all conditions are perfect but in reality 6 to 10. Your di is removing quite abit. Since tds is an equation based on a number of parameters the conductivity even with low tds is still quite high. So in short the di is doing more than meets the eye.

Don

 

[jus85411]

i was talking to someone off craigslist that my buddy bought a 110G from yesterday. he has holes drilled on the bottom of the glass aquarium with two "filters" sticking up out of the bottom. a bunch of PVC linking the pump to the "filters" and pushing back out into two other drilled holes in the bottom of the tank.

now for my real question im trying to find out for my friend:
when you have a RO/DI unit for purifying your water, do you really not need any filter media for the tank(i.e carbon, ammonia chips, sponges)? i dont know much about these RO/DI units yet, am doing some reading up on them and hopefully get one eventually.

i know this guy knew his stuff, he has a 180G in his living room with about a dozen decent sized discus in it, and it was crystal clear. but i was just a little iffy about no filter media regardless of what the guy knew. he even had a big cichlid in the tank still when my friend went to look at it. the water in the tank was crystal clear, the fish was healthy and the "filter" setup he had was kicking ass. he said the only thing he does is one week take off one sponge, rinse it off real good(not in tap water) and the next week rinse the other one. he never did water changes apparently and he had minimal maintenance to do to it.

 

[Herefishyfishy]

Welcome to Reef Frontiers!

Salt water aquariums have many more needs than most fresh water systems. Starting with totally pure water before adding the salt mix will prevent many algae and other toxic metal problems that could crop up later down the road. Even after starting with pure water, filtration will be needed to keep it relatively clean.

 

[jus85411]

thank you! seems like a very useful site. i was directed here by someone from Monster Fish Keepers for questions i may have for my salt setup, as well as setting up my sump/refugium i plan on doing shortly. hes using the 110G for his freshwater set up. my worry was because there are some fish in the tank(including my polypterus senegalus) that were relatively small when he first set up his 45, and i worry about the no filter media thing because i certainly dont want to see this fish i have been watching for the past 6 or 7 months grow up die on me. especially being my contribution to his tank and it being the only fish left from the very beginning set up. hes been through a lot. and grew from a mere 2 inches or so when i first got him to now like 6 or 7 inches. we were already planning out last night right after we got it home how we can reroute the intake of the water pump to this sectioned off part of the tank that is attached to the back of the tank so essentially we make that whole piece of the tank the filter with all the media, then reroute the put out of the water pump to whatever PVC tubes we want to be the water feed back into the tank. now i thought with all glass aquariums you cant drill holes in the actual bottom piece of glass? isnt it tempered? should we be worried about the weight of the substrate he will be using and it possibly doing something to the glass?

 

[jus85411]

and i have never heard of no filter media needed, so it was definitely mind boggling