Water Management System

[gothunder3022]

With some inspiration from Bricky, I just finished setting up my new water management/storage system, and thought I'd share some photos and comments on my design while it's undergoing its maiden voyage!

I wasn't happy with the amount of waste water I was getting from my RO/DI production and was looking for ways to cut it down. I was getting at least 4 gallons of waste for every gallon I made. I've been dealing with TheFilterGuys for my equipment (quick shout out to some really great people...I highly recommend them!), and they recommended that I double up my membrane. I did, and that cut the waste by a little less than a half, to maybe 2.5 gallons of waste for every gallon of RO/DI. This was all fine and good for my needs...a 28 HQI nanocube...but then I got bit hard by the reefing bug!

So I have 3 small tanks at the moment, and am in the process of setting up 3 larger ones....I need lots more water!

As I planned these new tanks, I kept coming back to the waste water issue, and with a relatively low starting TDS of 34 I started looking into ways to minimize the waster further. Plus I wanted to develop a system that would simplify my water changes.

I learned that adding a 3rd membrane to my setup wasn't going to work, plus I was looking for a way to re-process the waste since the TDS was still pretty low after the first pass...only 60 something TDS.

Here's what I came up with:
I use two RO/DI units, one 150 gpd and one 75 gpd, both have dual membranes. I have two 200 gallon poly storage tanks (one for saltwater and one for RO/DI), and one 300 gallon poly waste tank. I have one Aquatec 8800 (more on this later) and 2 Iwaki 40RLXT's for circulation and distribution.

I run my water supply to the 150 gpd (I have about 80-85 lbs of pressure all the time), which empties into the RO/DI unit, and then I feed the waste line into the inlet of the Aquatec booster pump. The output of the booster pump goes to the supply side of the 75 gpd, which feeds into the RO/DI, and drains into the 300 gallon waste tank. I can select float valves at 100 gallons or 200 gallons on the RO/DI tank that, combined with a pressure switch for the booster pump, shutdown the system automatically when the desired volume is reached. I also have the system set up where I can re-process the waste tank water through the 75 gpd RO/DI unit.

The two systems running together produce almost 10 gallons per hour, with slightly less than 1 gallon of waste for every gallon of RO/DI. The resulting waste TDS is 74, so I'm hoping I can re-process half the waste without frying my membrane prematurely. Ultimately I should be able to produce 300 gallons of RO/DI with only 100 gallons of waste.

As for storage and distribution, I have an Iwaki plumbed (one each) to the Saltwater and RO/DI tank in a closed loop for circulation, as well as distribuiton valves so I can pump the water where ever I want through a hose. The tanks also have gravity drains, and the RO/DI tank is cross connected to the Saltwater tank for filling.

So far it's working as planned...and now (finally!) some pics:

The RO/DI units:

The RO/DI and Saltwater tanks:

A shot of all three tanks:

The pumps and circulation/distribution plumbing:

The combined inlet to the 200 gallon float switch (I run two 1/4 lines into a 3/8 float valve):

 

[Tbremer]

nice set up looks pretty efficient. Im currently working on a water management system for my 75 gallon that i am going to set up here in a month or two. Hopefully i will be able to get pictures of the whole thing once im up and running. What did you use for a float valve?

 

[gothunder3022]

I used these:
http://www.bigbrandwater.com/floatvalves6.html

Probably overkill, but I thought a 1/4" float valve might cause back pressure.

 

[jhampton_wsu]

How much does a gallon of water cost you in Maple Valley?

 

[gothunder3022]

negligible...I think 4-5 cents per gallon.

 

[Bored4ever86]

negligible...I think 4-5 cents per gallon.

have you run the numbers on how much cost/gallon you reach with all the costs involved (electricity, supplies, membranes, etc.)?

I know its highly efficient in terms of reducing waste water, but it seems like all the money invested to reduce the waste outweighs the cost of the water. Heck waste water is great for lawns, washing machines, and, if you can figure out how, showers.

Congrats on the system, hopefully you can figure out a way to reduce overall costs even more.

 

[roscoe]

Here is a couple of units that is really great on waste water to good water ratio without having to do all that.


This one is the best as it has a 1:2 good to waste water ratio. That is 2 good gallons to every 1 gallon waste. http://www.spectrapure.com/low_waste_systems.htm

This is what I use but the 100gpd model. It has been great for me. It actually produces around 120-130gpd. It has an almost 1:1 waste to good water ratio. I'm able to fill my 55g container in 10-11hrs.
http://www.marinedepot.com/Puratek_...ems-Vertex_Aquaristik-VX3111-FIRORDNH-vi.html

 

[Chichas01]

Why not just pump the waste back into your water supply for your home? I've heard others do this with a pump. Never seen it myself tough. Not sure if the city would be happy, but how would they know?

 

[gothunder3022]

have you run the numbers on how much cost/gallon you reach with all the costs involved (electricity, supplies, membranes, etc.)?

I know its highly efficient in terms of reducing waste water, but it seems like all the money invested to reduce the waste outweighs the cost of the water. Heck waste water is great for lawns, washing machines, and, if you can figure out how, showers.

Congrats on the system, hopefully you can figure out a way to reduce overall costs even more.

Well, I guess I over emphasized the waste water side of the equation a bit.

Ultimately I wanted the ability to make, store and distribute a much larger quantity of water...and I'm sick of buckets and trashcans. My original RO/DI unit, storage tanks, plumbing and the iwaki's are all necessary for that. So I consider these outside the cost of the extra waste processing.

Since I'm not set up to reuse the waste I was thinking more about simply reducing it versus the cost/benefit ratio. But you got me thinking, and it goes something like this:

The additional cost for minimizing the waste includes the 2nd RO/DI and booster pump...something on the order of an extra $500. I just finished my first 100 gallon batch, and ended up with 88 gallons of waste (not too shabby!). I'll be making at least 400 gallons monthly, so the difference in my original waste (at the 2.5:1 waste to good) is 648 gallons (400*2.5 - 400*.88). At a nickel a gallon that's $32.40 savings per month, so it'll take a little over 15 months to realize the savings. Of course this doesn't factor in the additional membrane and prefilter costs, which remain to be seen. I won't calculate the additional electricity cost for the booster pump because it's pretty negligible, plus I've probably bored you to tears at this point!!

 

[gothunder3022]

Here is a couple of units that is really great on waste water to good water ratio without having to do all that.


This one is the best as it has a 1:2 good to waste water ratio. That is 2 good gallons to every 1 gallon waste. http://www.spectrapure.com/low_waste_systems.htm

This is what I use but the 100gpd model. It has been great for me. It actually produces around 120-130gpd. It has an almost 1:1 waste to good water ratio. I'm able to fill my 55g container in 10-11hrs.
http://www.marinedepot.com/Puratek_...ems-Vertex_Aquaristik-VX3111-FIRORDNH-vi.html

"all that"! But it was so fun to put together!! As you'll see in my last post, a lot of all that is for more than just waste reduction.

That spectrapure looks awesome...but my two systems w/booster is cost comparable. I suspect I'll spend more on membranes and filters though. That Puratek unit that you use looks very cool...I'd definitely look into it if I was starting from scratch.

One thing to consider about the advertised waste to good ratios, though. Membranes are rated at ideal temperatures (like 77 degrees)...my water runs much cooler at 50 degrees, which reduces the efficiency of the membrane. Do you know if you're only getting 1 gallon of waste on your system?

Thanks for the feedback, btw!

 

[gothunder3022]

Why not just pump the waste back into your water supply for your home? I've heard others do this with a pump. Never seen it myself tough. Not sure if the city would be happy, but how would they know?

I'm not sure how I'd do this...I guess I'd need some sort of demand pump that exceeded the 80-90 psi of my city supply.

People talk alot about using the waste for laundry, toilets, landscaping, etc. Sounds like more buckets to me!

 

[roscoe]

"all that"! But it was so fun to put together!! As you'll see in my last post, a lot of all that is for more than just waste reduction.

That spectrapure looks awesome...but my two systems w/booster is cost comparable. I suspect I'll spend more on membranes and filters though. That Puratek unit that you use looks very cool...I'd definitely look into it if I was starting from scratch.

One thing to consider about the advertised waste to good ratios, though. Membranes are rated at ideal temperatures (like 77 degrees)...my water runs much cooler at 50 degrees, which reduces the efficiency of the membrane. Do you know if you're only getting 1 gallon of waste on your system?

Thanks for the feedback, btw!

I hear ya about "all that":lol:. It i fun building stuff. Anyhow with my Puratek I can safely say it produces 1.5:1 ratio consistantly and even better when the wheather is warmer. As a matter of fact I just replaced the pre filters and DI last night and made 50g in less than 10hrs.

 

[MrGone]

That is a really cool setup!

If you don't mind, where did you get those large storage containers?

 

[gothunder3022]

The Tank Depot...there are several similar sites. These are the tanks I bought: http://www.tank-depot.com/productdetails.aspx?part=TN3169IC

Unfortunately it looks like the shipping costs have really gone up. I paid $80 for two tanks to a commercial address this last winter (they charge more for residential delivery)...looks like that is now up to $126.

You might be better off trying to find someone selling them local.

 

[gothunder3022]

You can pick them up from the distributor in WA...but it's way down on the WA/OR border.