Greenhouse project

The RO system is a commercial model made by Spectrapure (actually, everything you see came from Spectrapure). It is a new model called the PSP1000. In ideal situations, it can make 1000 gallons per day at a 1:1 ratio of clean to waste water. My conditions are far from ideal though because my water is so cold. I expect to get something closer to 600 gallons per day. The nice thing about these units is that the membranes last a very long time. Tech support at Spectrapure told me it is not uncommon for a membrane to last years if properly maintained. It was news to me that a RO membrane could be "maintained," but this system has a second pump in it that is connected to the clean water reservoir. When the system is inactive, it turns on and back-flushes the RO membrane allowing it to soak in clean water while not in use. Supposedly, it extends the life of the membrane which is good because a replacement will cost me somewhere in the neighborhood of $250.

I do not have a DI system yet. I was going to see how low the TDS will be without one. If the reading is relatively low (under 100 would be nice considering I am starting at about 850), I might just skip it.
 
dendronepthya said:
I do not have a DI system yet. I was going to see how low the TDS will be without one. If the reading is relatively low (under 100 would be nice considering I am starting at about 850), I might just skip it.

Interesting. My tap water in MD has 130 tds. After the RO membrane it would come out to 4-6. It was 0 after DI. I am in FL now and the TDS is well past 1000. Heck, you can see how dirty it is as I fill the tank for a water test of the plumbing. I will use NSW because it does comw much cheapper than RO/DI even if you pay $0.5/g of nsw.:rolleyes: :rolleyes:

11006Resize-Assistant-1-med.jpg
 
Glad to hear you like the pumps. I'm having a heck of a time calculating which one I need. I'm happy to see you got a good water system up. After reading about your water conditions I though it might put a damper on things a while.

Any ideas of how much evaporation you are getting?
 
Glad to hear you like the pumps. I'm having a heck of a time calculating which one I need.
I never bothered trying to calculate. I bought the biggest linear piston pump they sold and tried it out. I figured if the output was greater than my air system's requirement, I could always bleed off the excess air. I hoped a single pump could power my entire setup, but that wasn't the case. I needed a total of three pumps to do that job.

Any ideas of how much evaporation you are getting?
Surprisingly little. If I had to guess, I'd say 10 gallons for every 750 gallons. So, assuming all three of my systems are running, that would be 30 gallons per day. Sounds like a lot, but when you consider the systems are going to be in the neighborhood of 2500 gallons total when completed, it's really not that big of a deal.

dgasmd,
That's how my water looks. It's actually strange, it will be clear for a little while, then start to turn yellow like that. After a few days, it precipitates corn flakes of calcium and magnesium. Just nasty stuff. The crummy water is one of the major reasons I decided to get a very dedicated water purifier. The corals I have placed in the "test" tank are still alive for the most part, but I am getting nasty algae growth, and the chemical parameters are all out of wack. I am hoping that once the system is up and running, I will get RO water for less than $.10 per gallon.
 
dendronepthya said:
30 gallons per day.

Ok - so stupid question,

If your needs are 30 gal per day in evaporation - and even figuring a rather agressive water change of 10% per week (250 gallons), you're looking at about 460 gallons per week, or 65 gallons per day. Wouldn't a 100 gpd unit (at around $200) have been "good enough"?
 
That's not a stupid question. There are three major reasons for the decision to go with the big unit over the small unit.
1. The issue isn't really day to day production, it is long term cost of replacement. While a 100 gpd unit would produce the quantity needed, the membranes and pre-filters would be quickly expended. Most people with 100 gpd systems do not make more than 30 gallons a week I am guessing.
2. Waste water. A typical RO system gets about a 1:4 ratio of clean to waste water. On a hobby scale, it's not a really big problem. You can use the waste water to do some laundry or water the yard. When you are now talking about hundreds of gallons of waste water per day, you see the problem. All of that water has to go somewhere. The large pumped units get 1:1 ratios because they recirculate the water.
3. There was a 500 gpd system similar to the 1000 gpd system that was more in line with my needs. After you factor in the reduced production from the cold water and pH, it would produce about 300 gpd which would probably have sufficed. The reason I went with the 1000 gpd unit was there was practically no difference in price between the two systems. Why not pay a little extra to get double the capacity?
 
Great thread. Just wondering if you had any new pics of your corals. I am just starting out and would love to purchase some home grown coral, less effect on the environment.
 
Surprisingly little. If I had to guess, I'd say 10 gallons for every 750 gallons. So, assuming all three of my systems are running, that would be 30 gallons per day. Sounds like a lot, but when you consider the systems are going to be in the neighborhood of 2500 gallons total when completed, it's really not that big of a deal.


I have a 90 gallon tank and I do 3-4 gallons a day.

Man, what am I doing wrong.....
 
I doubt that you are doing anything wrong. More than likely you have a lot of lights under a hood that are very close to the water surface. The heat will contribute a lot to how much water is being evaporated from your tank.
 
dendronepthya said:
The RO system is a commercial model made by Spectrapure (actually, everything you see came from Spectrapure). It is a new model called the PSP1000. In ideal situations, it can make 1000 gallons per day at a 1:1 ratio of clean to waste water.

Than,

Any idea what make/model membranes your unit uses? IIRC Spectrapure uses Dow Filmtec membranes for their residential systems but I'm unsure what they use for their commercial pumped systems. I have some clients that use Filmtec membranes but I think GE makes them in those larger sizes too.

Awesome project BTW - I've been lurking since day 1 but haven't had any reason to speak up till now.
 
wonrib00 said:
I doubt that you are doing anything wrong. More than likely you have a lot of lights under a hood that are very close to the water surface. The heat will contribute a lot to how much water is being evaporated from your tank.

I am running 1- 400 MH , 4 110w VHO. amd all are about 18 - 24 inches off the water level
 
Howdy,

I am curious about the water softener. What does it do? I mean I know what a water softener does, but why put one in line when the RO membrane will remove the salts the softener adds? Does the softener improve the performance of the membrane somehow?

Thanks,

Scott.
 
Using the softener to knock the worst out of the water significantly improves the performance and life of the membrane. It's common industry practice for large RO systems.
 
What der_wille_zur_macht said is correct.

A water softener replaces many of the ions in the water with sodium. Calcium, magnesium, iron, etc. get bound up in the resin and sodium gets discharged. The RO system can handle sodium very easily, but the other ions listed tend to form scale deposits that clog up the membrane over time. By swapping out most ions for sodium, the water softener extends the life of the RO membrane.
 
Weird wild stuff, I did not know this! YES!!!

So would adding a water softener to my current RO/DI setup make it more efficient? I have a water softener that was used by the previous owners of my house, but has been sitting there gathering dust since I moved in.

I'll have to give it a try.

Thanks,

Scott.
 
srbayless said:
Weird wild stuff, I did not know this! YES!!!

So would adding a water softener to my current RO/DI setup make it more efficient? I have a water softener that was used by the previous owners of my house, but has been sitting there gathering dust since I moved in.

I'll have to give it a try.

Thanks,

Scott.

IMO it would be hard to justify a water softener dedicated to a small residential RO unit at the low production levels us hobbyists are likely to use. If you're gonna do anything with it, why not just plumb it into you're house's water supply and benefit your whole home?
 
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