TotesMaGoat Posted October 28, 2015 Share Posted October 28, 2015 I have 40psi going into my rodi unit. I know 50 is usually considered the lowest optimal, at what psi are you guys adding a booster pump? Ive got a 5 stage brs 75gpd unit ive got 5tds going into the di and 1 coming out. I have a 40 display plus 20 sump, so im thinking ill probably need 2-3 gallons a day at most for topoff so should get me by just fine, but would be nice to make it quicker, also maybe get the tds down to 0? I bought the unit used, but its color changing DI resin and 3/4 still looks good. Getting just over 4:1 waste to clean Link to comment
AZDesertRat Posted October 28, 2015 Share Posted October 28, 2015 40 is about the bare minimum pressure a RO membrane will operate at. An Aquatec 8800 RO booster would quickly pay for itself in DI savings alone. Never rely on color changing resins, they are notoriously inaccurate. Get yourself a good handheld TDS meter such as a HM Digital TDS-3, TDS-4TM or AP-1 and use it on a regular basis. You need 3 TDS readings not just 2, tap TDS, RO only TDS and final RO/DI TDS to know how your system is working. Since the RO membrane does 90-98% of the work you really need to have the tap TDS and RO only TDS readings to calculate the rejection rate or removal efficiency. Often a membrane may be performing poorly and the DI is used as a crutch to prop it up, anbd gets expensive in replacements. Raising the pressure from 40 psi to 80 0r even 90-100 psi willmore than double your GPD, up to around 130-150 GPD at 90-100 psi, but better yet the rejection rate will probably go up tremendously. This is important since for every 2% you can increase the rejection rate, such as 96% to 98% etc, you double the life of your DI resin. You want to make treated water in larger batches, say 5-10 gallons or more at a time so the system stays well flushed via the waste line and flow restrictor. Small batches contribute to TDS creep and shorten the DI life. You mean 4:1 waste to clean don't you, not 4 clean and 1 waste? Link to comment
TotesMaGoat Posted October 28, 2015 Author Share Posted October 28, 2015 thanks for the quick response. Yes i meant waste to clean, sorry. My tap is right about 200 tds and ive got 5 tds coming out of the ro.Very calcium saturated water around here. my total output will be fine i believe even with 40psi, making little more than a gph, but if a pump means I can get that 5tds down lower before the DI. Like I said I still have 1TDS coming out of the rodi and i bought the system used so i am tempted to buy all new filters possibly ro membrane as well. Link to comment
braaap Posted October 28, 2015 Share Posted October 28, 2015 thanks for the quick response. Yes i meant waste to clean, sorry. My tap is right about 200 tds and ive got 5 tds coming out of the ro.Very calcium saturated water around here. my total output will be fine i believe even with 40psi, making little more than a gph, but if a pump means I can get that 5tds down lower before the DI. Like I said I still have 1TDS coming out of the rodi and i bought the system used so i am tempted to buy all new filters possibly ro membrane as well. If you bought it used sell it. Try and buy the spectrapure refurb unit. Then buy a booster pump. Pressure is your friend when it comes to RO/DI units. Spectrapure Link to comment
TotesMaGoat Posted October 28, 2015 Author Share Posted October 28, 2015 If you bought it used sell it. Try and buy the spectrapure refurb unit. Then buy a booster pump. Pressure is your friend when it comes to RO/DI units. Spectrapure All i need is a booster pump, there's nothing wrong with the unit Link to comment
Mr. Clownfish Posted October 28, 2015 Share Posted October 28, 2015 Just wondering how a booster pump would be effected if I'm using a float valve at the other end to shut off the water when my storage tank is full? Link to comment
TotesMaGoat Posted October 28, 2015 Author Share Posted October 28, 2015 Just wondering how a booster pump would be effected if I'm using a float valve at the other end to shut off the water when my storage tank is full? most pumps come with a pressure switch Link to comment
AZDesertRat Posted October 29, 2015 Share Posted October 29, 2015 What he means is the cost of high quality replacement filters, a high rejection rate RO membrane and matched flow restrictor and a new DI cartridge will just about equal the cost of a new Spectrapure reef quality RO/DI. If you have high calcium the absolute best thing you can do for a RO system is install a water softener, RO membranes love soft water since much of the work is already done. If you have an ASOV or auto shutoff valve on your RO/DI you need a Aquatec booster pump with a pressure switch so it shuts off when it senses the ASOV is closed due to a rasied float. Link to comment
TotesMaGoat Posted October 29, 2015 Author Share Posted October 29, 2015 What he means is the cost of high quality replacement filters, a high rejection rate RO membrane and matched flow restrictor and a new DI cartridge will just about equal the cost of a new Spectrapure reef quality RO/DI. If you have high calcium the absolute best thing you can do for a RO system is install a water softener, RO membranes love soft water since much of the work is already done. If you have an ASOV or auto shutoff valve on your RO/DI you need a Aquatec booster pump with a pressure switch so it shuts off when it senses the ASOV is closed due to a rasied float. my rejection rate at 40psi is 97.5%, id say membrane is just fine, throw 40$ in for new pre filters/DI resin/CAC and it'll be good to go. I have refillable DI canister. Only spent 60$ on the unit. Live in an apartment so softener is a no go. 200tds pre ro 3tds post ro, even with these used filters with who knows how many gallons through it, is pretty manageable. I think just the DI is spent because its 3 pre di and still coming out at 1tds post, but am replacing everything minus ro membrane for peace of mind. Will have a booster pump on the way soon so I should see my rejection rate come up as well Link to comment
Recommended Posts
Archived
This topic is now archived and is closed to further replies.