Impurities after RO/DI filtration?

[Tazmaniancowboy]

Is it possible that any of the nasties that we do not want to see in our reef tanks can make it past an RODI even with a TDS reading of zero? eg. silicates, phosphates, iron etc.

Is a DI resin bed standard or do you need specialized filters/resins to take out silicates?

Taz

 

[Hawkeye]

I'm not sure myself but a TDS of 0 is better than a TDS of 300. One thing to consider is that LR and sand that is reused could potentially leech things back into the water column (e.g. phosphates).

 

[justchad]

this I can tell ya. If your running a mag pump or any other pump that has metal screws, it can release impurities into the system, and as far as tds readings, I have learned from my own experience that 0 tds is great for sps but higher tds is great for the growth of zoos. before i learned about my high tds, my zoos were multiplying and growing like weeds but my sps had no polyp extention. I upgraded the rodi and now i run 0-2 tds and have great polyp extention but I am loosing most of my zoos. :

 

[Bruce K]

Is it possible that any of the nasties that we do not want to see in our reef tanks can make it past an RODI even with a TDS reading of zero? eg. silicates, phosphates, iron etc.

Is a DI resin bed standard or do you need specialized filters/resins to take out silicates?

Taz

Silicates are the one impurity that will get through an RO and DI. A good DI will stop some but not all of them. There is a regenerating resin specifically designed to take out silicates (and humic acids) that is run after DI. I have only sold these to commercial propagators. Unless someone has very high silicates after their filtration, I do not think it is necessary to add this expense.