Ro-di

[humptrax]

Hi Randy,

i'm currently looking to purchase an RO-DI unit but the model that i'm currently looking at does not provide a pressure gauge housed within the unit. obviously, without a pressure gauge, the performance of my filter can fluctuate significantly so i was wondering if there was a way i can modify the filter itself or if i should look for another unit. how important is it to be able to tell the pressure going through the unit. obviously, it could tell me how quickly and how much the filters/resin have depleted but i mean, will running pressure outside max efficiency effect the performance enough on a filter to where i should consider purchasing another unit?

Thank you always for the wealth of information.

 

[Randy Holmes-Farley]

I find the pressure gauge very useful for knowing when the sediment cartridge is shot. one could add one, but you'd need to add it carefully just before the RO membrane to be most useful.

If the pressure is too low, the efficiency and the output both drop, especially the output.

 

[humptrax]

i got some stats for the tap water quality here in atlanta but really, the numbers mean nothing to me...

i've decided that yes, i do need a pressure gauge to make sure that the filter is working at optimum efficiency. i'm already losing 3 parts water per 4 that i fill so the last thing i need is crappy water coming out of a terribly inefficient process...

i've narrowed my choices down to two. i'm not sure if you're familiar with these brands but i've decided on either a spectrapure unit or the typhoon III. the cost difference between the two units is more than double for the spectrapure. the main difference between the two seems to be the 2% higher rejection rate in the spectrapure unit.

i posted a thread on the lighting/filtration forum but no one seemed to be interested in answering my question.

so, i turn to you, in hopes that maybe you can help me make the best purchase i can. is the 2% increase in rejection rate really worth over double the price? i'm not exactly well off and reef keeping is really eating my cash so the $280 difference between the two units is huge to me. i figure if the tap water quality is good enough, then the 2% wouldn't make a huge deal but i guess i just wanted a second opinion.

here's the water quality parameters for my town:

http://www.gwpca.org/ccr/2002Small_System_Booklet1.PDF

i've learned so much from your writings, i couldn't thank you enough.

thanks again.

 

[Randy Holmes-Farley]

I've been using the same Spectrapure unit for 10 years with no problems at all.

I wouldn't focus on the rejection rate itself as important, but I don't know enough about the membranes that they actually use to say which is the better way for you to go. If I were to buy another, I'd get another Spectrapure unit.

 

[lessans]

I just bought the Coralife Pure-Flo II 50 GPD? What do you have to say about this unit, Farley?

 

[Randy Holmes-Farley]

I am not familiar with it.