I am thoroughly confused here. If you are drinking the RO waste water and using the RO waste water for your tank, what are you doing with the pure RO water you are making and why are you making it at all? In order to have RO waste water you need to be producing pure RO water too. What am I missing here?
Are you simply bypassing the RO filter and running tap water through the micron, carbon and DI chambers?
Sorry I missed this question you posted earlier Randy, I'm just ignoring the teens and tweens here.
Before I set the tank up I had the RO and wastewater teed to the same line and that's what we were drinking. As per the bottled water link I posted earlier, I think drinking that water was harmless.
I started the tank (cycling the rock) with conditioned tap water. Then I filled the tank with the same water we were drinking, a mix of RO & wastewater figuring if we could drink it, the fish can live in it.
IMHO 30-40ppm TDS isn't gonna kill us.
Also, I knew the rock would be leeching minerals back into the water so using pure RO would be fruitless at that point.
So in = tap---Fine
Out = RO----Fine
Where is the 3rd waste line going? You seem to indicate that it is looped back into the Out w/ the RO somehow which means you are mixing the RO and the waste which essentially gives you the same water as before it went through the RO membrane. Why bother at all? You are accomplishing nothing for your water quality beyond passing it through the micron and carbon stages prior to the RO membrane. Just pull the RO membrane altogether and filter through the micron and carbon and you'll have fine drinking water without waste ( think Brita) and then you can run the same ( ill-fated imo) experiment on your aquarium you intend to run on carbon filtered tap water.
Drinking water has plenty of minerals in it and thus a measurable TDS, so I don't understand your last post at all. Reef Aquarium water needs to be VERY low in TDS for long -term success. NYC tap water is quite low in TDS, but one thing it is not low in is PO4 which is actually added to the water supply and carbon and micron filters will not remove it. RO membranes and/or DI resins will.
After setting up the tank, I "rewired" the RO filter in that the wastewater goes up to the faucet (for now) and the RO water goes into my bucket. I also added 1 micron sediment filter and 5 micron carbon filters yesterday.
After further testing I got a rating of 0ppm TDS at the RO out while the faucet (wastewater) was running. When I turn the faucet off the RO out goes as high as 10ppm TDS.
I have yet to test the wastewater for TDS but since it is so low from the tap I feel this is unnecessary.
I did test for PO4 and got a measurable reading so going forward I will use 0ppm TDS RO water for the tank and utilize a PO4 additive (like Phosban) to adsorb PO4 for the long-term success of the tank.
Thanks for posting here and I look forward to lengthening our discussion.