ro/di water filter
 

Hi Reefers,

What I've made isn't anything out of the ordinary but a takeoff from a traditionally RO/DI system… I needed to make a system as good as the on-line units but better without killing the price.

So first I looked at the components in the ordinary units and I found the same in all of them, the sediment filter. All the units I found on-line and at shops are using a 5 micron filter…why?

Second was the selection of carbon blocks, RO membranes and what drove me crazy was the unorthodox 5th stage (refillable cartridge) … if I was to buy a five stage systems sold on-line my wife would have divorced me over the wall the I’d need to install the unit on...lol

I set out to make a better unit and still stay around the on-line prices of about $200.00

This is what I bought in parts and assemblies for $200.

1) Stage one – a re-washable 0.5 ceramic sediment filter, can last a very long time as long as you don’t drop-it.
2) Stage two – Pure-flow T33/CG coconut activated carbon chips.
3) Stage three – MatrKX+CTO/2 carbon block (also .5 um filter)
4) Stage four - Dow Filmtec TFC 100 GPD RO membrane (not a 50 or 75GPD, I don’t have the patience to wait all day for a pal of water).
5) Stage five – an in-line DI filter housing that clips to the membrane housing, I wanted the unit to be a standalone portable unit.
6) Than for the whistles and bells I added flushing kit, auto shut-off valve, float switch and 3/4 to 1/4 adapter.

Here a picture…

As long as it is 0 TDS that is all that matters.

you know the 100gpd membrane has a lower rejection rate than the 75gpd right?

if your tap water tds is low, you can skip the ro membrane stage altogether. you will replace the di resin more often, but thats about $12-$15 only per replacement, but that is offset by the sediment and carbon cartridge lasting 5x longer, since all water passing through it will end up in the filtered output, unlike with ro membrane where for every 1 gallon output, 5 gallon goes to waste. so the saved water counts towards offsetting the di replacement cost. plus you can fill up a 5 gallon bucket in about 10 minutes. I think fosteranssmith sells a filter like this, but it can be put together like the above by just skipping the ro membrane.

Where did you purchase all the parts? And did the skeleton holding everything all together come with one of the stages?