RO/DI systems

[AdamHorton]

I have an RO/DI system for my tank, and I'm not too happy with it. Here's a link to what I have:

Aquarium Water | Reverse Osmosis | RODI Water | ReefKeeper Water | TYPHOON III AQUARIUM RODI 75 or 100 GPD

I'm wondering if there's such a thing as an RO/DI system that doesn't create as much waste water or one that can generate pure water faster. It's about time for me to replace the filters on the unit I have and I'm thinking about just buying a different one.

 

[cabezon]

I believe that a high pressure pump can help, but I don't think a different filter will do it.

 

[AdamHorton]

So if I get a pump and hook that up to the intake from a reservoir, that will end up making pure water faster than just hooking it up to the sink or the faucet I use for hoses outside? I've never heard of that kind of a setup before...

 

[WhiteDevil]

Yes USWATER makes a unit that is a 1:1 ratio. I have it and its great.

I got a spectrapure MPDI25 unit that was a 1:4 ratio.

permeate pump is what uswater uses.

This is the unit I got
http://www.uswatersystems.com/shop/...-Permeate-Pump-System-w{47}4-Gallon-Tank.html

 

[neilanh]

I'm surprised to hear this. Everyone that I know that has the Typhoon line from AWI loves those units.

Waste is a side-effect of making RODI water. Typical waste to pure water is around 4:1, so you're going to have the waste. I've heard of 1:1 units, but never used them and honestly question their ability to do that. Personally, I use the waste to fill my fresh water tanks. Others collect it and water their plants with it. Finding a use for it is the best idea, because there's just no way to not have it, unfortunately, when producing RO water.

About your performance issues, I'm going to venture a guess (the same guess cabezon had probably) that your house's water pressure is too low to run the unit at max capacity. I have the same problem at my place.

Most RO/DI units need at least 50-75psi water pressure to operate anywhere near the spec, some require upwards of 80-100psi. There's a simple way to test your water pressure, get a unit like this one and place it inline before your RODI unit on the source water supply. This guage will tell you what water pressure you have.

If you find that your water pressure is low (like me, mines around only 30psi) then you can choose to install a booster pump similar to this one.

They're not cheap, unfortunately, but buying a different RODI system will not yield you any better results if your source water pressure is too low and you'll just be back here in the same situation with the new unit as well.

 

[WhiteDevil]

1:1 ratios are usually in the 5+ stage range.

I am fortunate to have 80+psi from my water supply.
A new unit wont cure the problem if its indeed the pressure causing it, they are products and they do have flaws at manufacturing, you might have a less then ideal unit that slipped thru QC. Its always a possibility but gauge your tap and see where you are at, remove the accelerators and/or diffusers from the faucet head before attempting to attach the gauge. The faucet heads aerate and increase pressure at times due to flow restrictions.

 

[AdamHorton]

I'll take a look at the pressure and see what I can do. If I had to guess the ratio of waste water to pure water, I would say it's around 50:1, and that's being generous.

I'll post back once I've figured out something about the pressure setup. Thanks for the help so far.

 

[WhiteDevil]

I'll take a look at the pressure and see what I can do. If I had to guess the ratio of waste water to pure water, I would say it's around 50:1, and that's being generous.

I'll post back once I've figured out something about the pressure setup. Thanks for the help so far.

50:1 is friggin nuts, how do you have it plumbed?

Im not sure what colors but you are tapped off the cold water supply then have it plumbed into the storage tank or?

 

[AdamHorton]

The way I have it set up right now is I have an adapter that goes from the kitchen sink to the input of my RO/DI unit, then from that to a storage bucket. I can also have the input come from my hose, since I have an adapter for that. I live in an apartment so I can't really do much with the plumbing that's already there. I know it isn't the best but I still think I can do better...

 

[WhiteDevil]

I never had my RO on the faucet adapter but I did have one of those tap water filters they sell that hooks up like that, The issue with those is you cant have alot of pressure on them or the lines pop off. I was with my tap filter(di unit) running it like that to initially fill my 45H and I was MAYBE getting 2gpd out of it that way, tons went down the drain but little made it to the tank.

You might be able to use a saddle valve on the lines under the sinks. that will give more pressure resistance.

 

[AdamHorton]

I have a water filter underneath the sink, which filters the cold water that comes out of that sink. That works pretty well, but I can't take much more liberty with the plumbing on that kitchen sink since I live in an apartment. I am planning on moving into my own home in March 2011, so I'll be able to do more there.

Come to think of it, I don't plan on having any corals until after I move, and during that process I'll inevitably do a 100% water change. Do you think there would be any harm in just using the filtered tap water instead of RO/DI water until then?

Past that, it sounds like I would have more luck hooking it up to the hose out back, which leaves me kind of screwed in the winter since I live in Ohio...

 

[corrado33]

I don't necessarily think messing with the plumbing is that much of an issue for something this small. I mean with a saddle valve once you're done with it, all you do is turn it off and no one will ever know it's there. (Assuming you installed it right, which is very easy). I think your problem is low pressure. If I understand correctly, you have the filtered water going to your sink, which feeds the RO/DI unit? So you're filtering the water, then giving it to the RO/DI? That filter is probably acting like a choke point, causing you not to have much pressure there. It's just my un(plumbing)educated guess though.

 

[cmor1701d]

I have a 6 year old Typhoon III. Last year I changed the membrane to the 150 gpd unit that AWI has. I've had a booster pump from them for 2 years.

Now when I make RODI water I get the rated amount. The water temp from the faucet is over 50 degrees and the booster pump is set to give me 70 psi (from the tap that's at 40 - 45 psi).

I also noted that my waste water is MUCH less than it was before the booster pump and increased temp.

In the winter I use a 25' coil for the intake tube from the pump that sits in a 5 gallon bucket with a heater. It heats the water a bit to help with the output.

 

[AdamHorton]

It makes sense that if the filter is operating under proper conditions (75 psi, 70-80F) it will have better output. It seems like pressure is my problem here.

So what you're telling me is that it's possible to have a booster pump between the faucet/hose and the filter intake to provide the adequate pressure? This seems like a more workable solution since it doesn't involve changing the plumbing in my apartment at all.

Last winter I noticed that increasing the temperature gives me better results for the filter, which is why I have about room-temp water coming out of the faucet. But it sounds like if the water coming from the faucet/hose is too cold, I can heat it up by submerging the intake tube in warm water.

So I have a couple of other ideas, and I'm sure you'll easily tell me why these won't work: What if I had a bin with 40G or so of tap water in it, and had my booster pump operate from that to the intake of the filter? Is there some kind of pump that works this way, or is this just a pipe dream?

Assuming that works, what if I piped some of all of the waste water back into that bin? Something about that sounds wrong but I don't know enough to say what it is or if it really matters... just bouncing some ideas around before I go spending money on this setup.

 

[WhiteDevil]

Something to take into consideration with apartments, there is only 1 supply coming into the building and it gets branched off to the needed units and common areas. that there is enough to kill the pressure completely. to a near well water trickle.

In your situation without a booster pump im not sure what else you can do besides nag the landlord for a pressure pump.