RODI Questions and more

[Falreef]

Just started using a BRS 150gpd water saver unit.* Pressure seems to run about 40-50.* I ran it for 1 hour as they recommend when first starting it up.*** Discarded all water.
Then ran the system and it produced 40 gallons in about 7 hours.* Fills up a 5 gallon bucket (I'm using a plastic water storage container, made to look like a water barrel, which has a flattened one side, meant to hold 40 gallons,*with a float valve installed in it) within 45-50 minutes.* Within 1 hour can have a 6 gallon bucket heated to tank temp 78F and saltwater and 5 gallons ready within 1 hour after that.** So fairly quick.* TDS going into the final membrane was about 3-4 initially.*
With TDS out reading 0.** However I noted that the water in the collections is running TDS 2-3-4, I don't know if this is good or bad.** I assume this is fine and it is usable.**
Now seems to run 12-14 coming into the last canister and 1 coming out of the last canister (final product)*according to the in-line TDS meter.
Question # 1:* Do you have to produce "O" TDS for it to be used?
Question # 2: Can RODI water of 1-5 be used?*
Question # 3: What would be the upper limit usable?

The pH however has me stumped.* The pH seems to run about 8.32-8.4 for the final product.* Would of thought it would have to be lower at 7.0 or just under with RODI.* My tap water is well water with a TDS around 125-135.* Waste water is about 200 TDS.
I'm planning to use the waste for my freshwater tanks.*
Question # 4:* Can you actually have a high pH for RODI water?* What causes that and how to reduce it.* I understand you can buffer up, but if it stays where it is 8.32-8.40 on the RODI, I don't have to do anything.* But what do I do if it is over pH > 8.4?

The BRS 150gpd water saver unit is fairly easy to set up and works well with the auto shut off as well as the float valve.** The price for this 5 chamber (really it is 6 chambers) unit is better than others that I have seen.* The unit is supposed to reduce the waste from about a 1 : 4 ratio of final product : waste water to about 1 : 2.
I still have to time that out and see what happens with volumes wasted and volumes produced, how fast, how much and measure and time it all out.

Too bad there is not an optional floor rack it can be mounted on.* Also flow diverter doesn't come with a garden hose to faucet connector, which is what is in most slop and laundry room sinks.** Took me a week to locate connectors that were needed - I have two.* The connectors the unit comes with are not labeled regarding the thread size and numbers.

I have a 30 Gallon JBJ rimless, now up and running 104 days, with fish, cleanup crew and a lot of coral in this tank.
I am running high Nitrates, but Phosphates fine at 0.25 and all other parameters are fine and stable.
Now with an RODI and preparing saltwater so quickly, I can do weekly or more often water changes if needed.
I also recently just purchased a Fluval 5 gallon EVO tank, to use as a holding, quarantine tank and for some corals and growing of frags.

Can anyone help me on these questions and provide any additional advice?

 

[theMeat]

The water entering the membrane should be at least 65 psi for a 150 gpd membrane. You either need a booster pump, a smaller flow restricter, or run a less gpd membrane for your 40-45 psi.
For well water you most likely don't need a carbon block, and more certain don't need two.
Particul filter.... since you have an extra canister, or two, now without carbon block, you can run more particul filters. The micron size you need varies from house to house. If you run a 10 micron and the particles are smaller. Like let's say 5and smaller, then the particles will pass the 10 and get caught in the 5 or smaller. If you run a filter rated smaller than the particles it will catch, like let's say run a 5 when the particles are mostly 10, than it gets clogged quickly. There's no way of knowing the size of the particles you're trying to remove without some testing/experimenting. Maybe run a 10 micron, 5 micron, a 1 micron, in that order of water flow. After some time you will see which filter gets the dirt and what micron sizes you should run moving forward.
Would not recommend using the waste water for your freshwater tank, unless it's a heavily planted tank in need of nutrients.
Don't know where you tapped the water source for your unit, but that may be the problem as far as low psi. Also, your well unit probably has an adjustment for psi

 

[theMeat]

Would say anything under 6 ppm is fine to use. The di resin is only supposed to take the final couple of ppm, which should be very small particles like silicates. 4ppm tops. If it is lowering more than 4ppm, than it will get exhausted quick and get costly. Without the proper psi your membrane is allowing particles to pass. For a 30 gal aquarium, if I were you would change the membrane to a 75gpd, with a matching size flow restricter, and call it good.
Would also double up on the float valve, or get an electronic one, to play it safe.

Final thing. Get that you're trying to save water, but running a 4 to one ratio, instead of 2 to one, will make your membrane last much longer. Would guesstimate that at 40-45 psi a 100gpd membrane will last 1,2, maybe 3 years if your flow restricter is well matched. Meaning giving you around 4-1 ratio. With that same 40-45 psi a 75gpd membrane will probably last 5+ years

Don't know if your flow restricter has a flush kit incorporated into it, but if it doesn't, for a few bucks certainly worth it