Waaaay too much waste water -- new Spectrapure CSPDI 90 unit


New member
Hi! Would appreciate any advice. I purchased a new CSPDI 90 Spectrapure RODI unit. Right now, I'm generating about 30 gallons of waste water (!!!!!!) to about 3 gallons of product water. Even though I'm using it for plants, it's a terrible waste. I understand the ratio is supposed to be 4:1. Any ideas for me? How do you work with the flow restrictor? Not sure how it all works.... Thanks in advance!

Vinny Kreyling

Premium Member
I would call them - sounds like something is hooked up wrong.
Flow restrictor is in the waste line & usually has to be cut in length to get the correct ratio.
Yours is WAYYYY OFF so let them help you.


Team RC
I have a flow restrictor that you turn, if I have it open water flows out of the waste line fast, if I close it restricts the water so it comes slower for the wastewater. I made that mistake the first time using it.


New member
I made an adjustable restrictor. I can dial it in exactly how i want


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Cheesehead Reefer
I made an adjustable restrictor. I can dial it in exactly how i want

I did something similar except I used a 1/4" Quick Connect ball valve on my wastewater line. Took a little tweaking to get the ratio of waste to product right. Works great, lasts long time.


New member
what does restricting the waste water do for how much waste comes out ...doesnt it just make the waste water run longer...so if i use up my two gallon storage tank..and the waste water runs for about two hours ..so now i restrict this wont it run for like 8 hours then???..im not getting this.......

Vinny Kreyling

Premium Member
Restricting puts pressure on the membrane forcing water through it.
Normally the ratio is 4 gallons of waste water to 1 gallon of product water.