What size r.o. tank?

[ScottP]

I'm in the process right now of converting a tandem bay into an automatic bay. When done I will have 2 self serve bays and 1 touch less auto(WW 2.0). I'm also getting rid of the D.I. tanks for spot free and installing a R.O. unit. I run the spot free in the self serve bays at 300psi. How big of a spot free tank should I use?

 

[madscientist]

do you mean the big "ace roto mold" drum (or similar) to store your spot free water?

what will be the production capacity of your ro machine? how many membranes and what size?

 

[I.B. Washincars]

There is really no right answer for this question. How much RO will your machine produce per day or actually how much will it produce for the daylight hours when the wash is in use? How many washes will go through your auto on a non-stop wash day? If your machine is a little undersized you will need more storage. Do you have a 4' door to bring it through? If you have a 3' you are somewhat limited. How much room do you have for a tank? I'm assuming you have a 4' door. If so I would get a 750 gallon vertical. It will fit through a 4' door and doesn't have a huge footprint. In most cases it will be ample. If you think it's too much you don't have to fill it all the way.

 

[MEP001]

We run a 3600 GPD RO system with a 300 gallon tank for a 6-bay (running 450 PSI) and single touchless auto. The RO system makes enough water to keep the tank filling on the busiest days.

 

[ScottP]

The R.O. unit will produce 3600 gpd. My distributor thinks a 150 gallon tank is big enough. One of his installers told me he thinks I need at least a 250 gallon tank. I have plenty of room to add a bigger tank. Is 150 gallon tank big enough?

 

[SteveJ]

I'm with the installer. I would go for the larger tank. It will enable you to have a bit of cushion if you have to turn off the production side of the ro unit for any reason. By the numbers, the machine should keep up with the demand but if it starts producing a bit less you are going to get tight. If I was sizing it I would put in a minimum of 500 gallons and prefer 750. But thats because I've ran out with a 300 gallon tank before when I made a slight adjustment to the ro. Not fun!

 

[MEP001]

Under ideal conditions 150 gallons would be enough, but if you run into problems you'd have a better "running buffer" with a bigger tank. If you have plenty of room, go with 250. The cost of the tank won't be much more.

Create a daily checklist which includes checking RO production. I can't tell you how many operators have called me when their tank ran dry because the membrane clogged up in a normal span of time, and they had no clue because they never looked at it and had no idea what it should be producing if they had.

 

[ScottP]

Thanks for the replies. We're going to add a 200 gal tank along with the 150. I feel much more comfortable with this.

 

[MEP001]

Why not go with a 300 or 350 gallon tank? It won't take up much more floor space than a 200 and will likely cost less than two tanks.

 

[mac]

You should also consider putting the tanks up in the air. It is pretty cheap to build a shelf that will support 500 gallons. Use a couple of I beams and sturdy planks and use horizontal tanks instead of vertical. Trust me, that extra floor space will come in handy for something.

 

[soapy]

I like the idea of 2 tanks because over time equipment rooms seem to grow smaller as you add stuff to them. My first wash I put in a 500 gallon tank and I have plenty of water and never come close to running out. On later installs I went with a 200 gallon tank for size reasons. On those locations I added a Hydrominder to the top of the tank and feed it with soft water. If the tank gets very low from being super busy it will add water to the RO if needed. If something happens to your RO system and it is down for a while the soft water will keep you running. I know it is not the same as RO but I have never had a water spot complaint when I have had to use soft water in place of RO for short periods of time.

 

[jprb]

If you have the space, use a 750 or 850 gallon tank and you shouldn't have to worry about running out of spot free water. We added a second 750 gallon tank when we added a second automatic bay.

JPRB

 

[ScottP]

The tanks are going in the second story, so they will be above everything. We have plenty of room upstairs but not a huge opening to get up there. We'll start with the two tanks and go from there. We can always add tanks when needed. I didn't want to be talked into just the 150 gal tank by the distributor. Thanks for the help.

 

[Kirb]

Where is the best place to buy RO tanks?
Thanks,
Kirb

 

[MEP001]

I've gotten them from a local farm supply place.