RO water

[fatman]

RO filters and their membranes are typically manafactured for optimum performance at operating pressures of 50 psi to 75 psi. Fifty psi should bring you up to at least thirty-five or fourty-five gallons per day with a waste to RO water ratio of 6 or 7 to one or maybe better. Depending on tye wtaer table and the rock or sand structure it is drilled in you may have to change your prefilters fairly often if you normally have much sediment or iron oxide in your water. I do not know if water there is high in silicates, if it is you will know by the diatom algae you have as a result of it. So much to learn with salt water tanks. Always new knowledge coming to light also. Well controls are pretty easy to deal with. High pressure and low pressure switches controled by springs around bolts with an adjusting nut for each one on each bolt. Two springs, two nuts , two bolts. Usually right at the pressure tank (captive air tank). Usually threaded into the check valve on the entry side of tnk. Usually a small plastic box about 4 inches square. If you need info just let me know.

[ravenfan8705]

Thanks a lot fatman, when I get home from work I will check it out. This definitly helps me out.

[Fastlight]

Bringing up an old subject and trying 2 understand this whole ro/di stuff im wondering what 2 do. I read on fatmans post that rodi units waste a lot of water compared to what you get out of it. I look up rodi units on the internet and i get a bunch of sites that offer 50gpd units at 250-300 bucks then i go on ebay and see this....
http://cgi.ebay.com/100-GPD-Reverse-...3286.m14.l1318

So is this a bunch of crap. is it a good unit? why r the ones on the internet so expensive?
Okay then what about when i first fill my 75 gal tank. Do i go buy 75+ gallons of rodi water or try and use thise 100gpd rodi unit? Yeah this whole saltwater aquarium stuff is making me dizzy.
I havent even begun to think about how im gonna initally do my first water mix 2 first fill my tank(mix the salt in)
Any help would be great

[RyanG]

That doesnt look like a bad unit or a bad price as long as you can get replacement filter easily. If you miss out on that auction check out www.purewaterclub.com for a wide selection of units.

[joeman]

Well it looks ok to me as well... I think your questions about price are applicable to everything right? Some things are cheaper than others for many different reasons. I bought my RO/DI unit from http://www.buckeyefieldsupply.com/ and have been very impressed / please with their (his ) customer service. He always responds to email or you can simply give him a call if you have problems / questions.
I don't see a pressure gauge on the one on ebay so you might want to think about buying one to add to it. It's the best way to tell if the filter is blocking (pressure climbs) - also usefull to set up your system and make sure it is operating at the pest pressure (around 50 ideally).
Oh yes, I would also get an inline TDS meter that will tell you the quality of the water coming out = best way to tell when your DI resin needs replacing etc...
Up to you whether you buy water to setup or not - I would use the unit if I had already bought it - just run the outlet tube into the tank and let it fill it slowly, then add the salt.

[Brat]

I would like to get this RO/DI unit
http://www.marinedepot.com/ps_ViewIt...s~vendor~.html

Any Thoughts?

[Bifferwine]

Spectrapure is considered one of the best brands for the hobby. But it is just so expensive. I got a 100 gpd, 6-stage unit off of Ebay for $100 including shipping. It's not a name brand, but I've made about 100 gallons per week with it since September and it still works great. I got it from the vendor that Ryan linked to (www.purewaterclub.com). I really see no need in spending 10x as much for a unit that will perform the same as my $100 unit.

[Brat]

well I don't need name brand if another one that is cheaper will do the exact same thing. I just didn't want so much water to be wasted with a RO/DI unit and I am reading how some RO/DI units have less waste water.

[Bifferwine]

Some do. The better brands waste less. A lot of people redirect the waste water to their washer so it gets used in the laundry, or outside to irrigate their gardens. I think Piggy does this.

[joeman]

yes they do. I too couldn't figure out why this was necessary because when I set my unit to push 100% of the water through the filter, my TDS meter still showed -000- so I dropped the guy at Buckeye an email to ask why his instructions told me to keep a ratio of about 4:1 (waste water : output). Here was his reply:

Re flush water: All the water you supply to the RO Membrane housing "in" port goes through the RO element – some of that water actually makes it through the semipermeable membrane within the RO element – the rest passes over this membrane at 90 degrees to the water going through the membrane. If you don't have adequate pressure, you'll get poor performance. If you don't have adequate flush water, you'll shorten the life span of the membrane by encouraging the deposition of scale within the RO element.

Russ @ BFS