Water main filter/ Water chemistry ?s

[DB junkie]

Looking for a little guidance here....

So I was looking at the RO unit here at work and it has a carbon filter, sediment filter, and 2 membranes.....

My question is which of these affects PH? IF I was to put a carbon filter on my water main as well as a sediment filter would this change PH? Or is it the membranes responsable for the filtering that lowers the PH?

What would be a good size (micron) sediment filter to run?

I keep rays. I'd like to be able to keep the PH a little lower than what I have now. Rather than 50/50 RO and tap can I just filter the tap a little less than an RO system would so I could just use that rather than mixxing.....

Thanks in advance for any advice....

 

[Mr Pleco]

Looking for a little guidance here....

So I was looking at the RO unit here at work and it has a carbon filter, sediment filter, and 2 membranes.....

My question is which of these affects PH? IF I was to put a carbon filter on my water main as well as a sediment filter would this change PH? Or is it the membranes responsable for the filtering that lowers the PH?

What would be a good size (micron) sediment filter to run?

I keep rays. I'd like to be able to keep the PH a little lower than what I have now. Rather than 50/50 RO and tap can I just filter the tap a little less than an RO system would so I could just use that rather than mixxing.....

Thanks in advance for any advice....

Here's what I run on my tanks with MO river water at my tap...I store my water for 24-48 hours in a seperate tank ( rubbermaid)..I treat the exchange /clean water with prime as directed . Inside the storage tank I use a Fluval inside filter with a Purigen bag ( reusable), and a heater..So the water in the storage tank is exactly the same as specimen tank...Because my water is so hard I also treat the water with Seachem Neutral regulator....because I'm on a city water supply it's less expensive than R0, no waste water and my fish are thriving in it....it allows me to do larger water changes with no PH and/or temp shock...

 

[DB junkie]

Seachem neutral regulator? What effect does this have on the water? What is your end result PH?

I really don't have the room to age/premix 300 gallons of water a day......LOL

 

[DB junkie]

No one else has any input here?

Getting pretty tough to find answers anymore.

 

[MadRussian79]

I use RO/DI system for discus. In truth all three will have some effect on pH. The carbon when new will have the least effect as it tends to remove larger molecular pollutants. They have an effect on the pH in the form of organic acids which while present should be minute. The main changes in pH are caused by RO and DI filters. I use both cause I got into the habit for my reef tank.

The advangte of RO is that the water will come out very pure but there is a load of waster water and you will have to re-mineralize the water which I do with Seachmes products.

The adavtage of DI is that id produces a lot more water a lot faster and not waste but it's not as pure. This is only an issue if your water is high in certain compounds. For reef tanks the copper is a major culpirt which will build up with top off water. Also a DI unit will not last as long as an RO/DI system.

Given that you already have rays and I'm assuming they are doing well you should easiliy get away with just a DI with carbon and sediment pre filter. If you are using DI I wouldn't be to worried about your sediment filter as this is mainly to protect an RO membrane it will etennd the life of your DI unit but it is not as critical. Check with other in your local area as sediments will vary with the source.

Could you post you water params both tank and tap for pH and KH, carbonate hardness.

 

[CHOMPERS]

^good answer.

I have only one thing to add. It's that everything has an influence on pH; some more, some less. When you remove those compounds, it changes the pH. That is why there is a pH change from all stages of the filter.

 

[brianp]

Looking for a little guidance here....

So I was looking at the RO unit here at work and it has a carbon filter, sediment filter, and 2 membranes.....

My question is which of these affects PH? IF I was to put a carbon filter on my water main as well as a sediment filter would this change PH? Or is it the membranes responsable for the filtering that lowers the PH?

What would be a good size (micron) sediment filter to run?

I keep rays. I'd like to be able to keep the PH a little lower than what I have now. Rather than 50/50 RO and tap can I just filter the tap a little less than an RO system would so I could just use that rather than mixxing.....

Thanks in advance for any advice....

In RO systems, the sediment and carbon filters are always located upstream of the RO membrane(s) and are essentially there to "protect" the delicate and finely-pored RO membranes against the accumulation of debris, clogging, etc. Water molecules "pile up" on the RO membrane and then move through the pores in response to a concentration gradient. On the other side of the membrane, the H2O dissociates to form OH- and H+. It is the concentration of H+ that determines the pH. I would expect RO water to have a pH of approximately 6.5. I don't think either the sediment or carbon filters are likely to have much affect upon the pH. One drawback to RO systems is that they typically waste lots of water. For example, you might have to process ten gallons of water total in order to generate one gallon of purified RO water.

 

[DB junkie]

So my options are.....

A) Lower PH with a well maintained RO system...... Then mixing that back with straight tap.

B) De-ionization which I will have to do more research into cause honestly I don't really know a whole lot about it right now.

Just seems kinda silly to me to filter it out then turn around and add back in 1/2 what you filtered out......

Right now I'm doing my daily waterchanges with straight tap water. I've used straight tap water ever since I got my first ray.... The more rays I put in the pond the more frequest the waterchanges. Now I'm up to daily waterchanges.

I can barely walk through my basement.....LOL The pond takes up half of it, now I need to fasion a means of having a holding tank and ro system rated at 150 gallons plus PER day..... Sounds like a pretty tall order I'm not really ready to make yet....

I'll see if I can locate a test kit for KH......

I'll have to do some research..... Anyone got any links for highly recommended DI systems?

 

[brianp]

Bear in mind, that I have not done this outside of the laboratory, but there is something you might want to consider. You could set up a container (let's say a 65 gallon rubbish container), fill it with water, dechlorinate and then add vinegar. In order to lower the pH, you must increase the H+. Vinegar is approx. 4-5% acetic acid and will dissociate to form [acetate + H+] when added to aquarium water. Biological system are loaded with acetate, so that component is irrelevant. You would have to determine the appropriate volume of vinegar to add. This would be inexpensive compared to the other methods you are considering. I see no theoretical problem with this approach.

 

[DB junkie]

Very small amounts of muratic acid would do the same wouldn't it?

Again we are back to the room problem though..... Right now I'm doing a rough average of 300 gallons when I do a daily waterchange. I don't know if I have the room for a 300 gallon mixing tub......

By the way I appreciate the replies......