Water Reservoir system ?'s- Please help

[DIYMatt]

I am in the process of reworking my RO reservoir system. This is what I had before. A 30? gpd Culligan Ro system with the 5 gallon pressure tank hooked up to a faucet on the sink. Then, I put in a tee and ran about 40' of 1/4 tubing(ice maker stuff from HD, I think its polyethelene) to a closet where I had a 30 gal or so, Rubbermaid tub as a reservior with a float valve to keep it full. It was mounted on a reinforced shelf over 6' above the floor. Then I ran a PVC siphon tube over the side connected to a brass faucet. Connected to the brass faucet was about 25' of 5/8" clear vinyl tubing normally used for filters with a hose shutoff on the end. The reservoir and hose would stay full of water pretty much all the time. I would fill my tanks with this system. I got sick of this thing in my closet and I got sick of not having RO while it filled the reservoir.

Questions on my old system and the water that is in my tanks: Recently, I have read about plasticizers in Rubbermaid tubs and even the filter tubing being toxic to plants/fish. Have I caused damage to my plants and fish already? What can I do about it now? How do I know what plastic is toxic and what is not?

Now this was my plan to make my RO system more efficent. I got a screamin deal on a new 60 gallon pressure tank designed for wells. I was going to move my RO system to my unfinished basement and replace the 5 gallon tank it came with, with the new 60 galloner and run the 1/4" tubing to the sink in the kitchen and to my closet faucet and hose. I have verified it will work from a plumbing perspective. Are there issues with the components I am using from a toxicity standpoint? Like the 1/4" tubing, pressure tank, etc. Is there a way to sterilize my new reservoir? Could the reservoir leach something toxic? What about my clear vinyl hose? What are the other options for non-toxic tubing and hose?

Thanks in advance for any help you can give or resources you can point me to.

[Cearbhaill]

How do I know what plastic is toxic and what is not?
Plastic is stamped on the bottom in a recycle triangle- numbers 1 and 2 signify food grade plastic which is totally safe for fish water.
Here (http://www.visionengineer.com/env/plastic_recycling_symbols.shtml) is a run down on what means what.

[DIYMatt]

Thanks for the info Cearbhaill, but I still would like some advice on the rest of my setup. Unfortunately, the tubing and pressure tank are not stamped with recycle signs like pop bottles are. Does anyone see any issues with my new proposed setup?

[chefkeith]

Sounds like your having a lot of fun setting this up. I posted a reply to you on another thread.

Here's the link-
http://www.aquariacentral.com/forums/showthread.php?s=&postid=136186#post136186

I wouldn't worry to much about the leaching, we pretty much depend on plastics to live. (or maybe I'm too trusting) Maybe check more into the RO system dropping your kh so much that its making your ph readings unreliable. I'm not sure though.

[DIYMatt]

Thanks Chefkeith, sorry it took me so long to get back on this.

I will address the reply to this post first.

Background on what RO water is:
RO water is water purified by reverse Osmosis. The RO process removes over 99% of everything, including ALL the hardness and buffers. Thats what I want it to do. So, being that the water is nearly pure the ph should be almost exactly 7.0(which is what it comes out of the RO filter at). So, even small amounts of anything will greatly affect the ph of the water. My reservoir had a constant amount of water in it, so I beleive the tub started to leach into my water.

Reason I use RO: My tap water is gross here and has a KH of about 18! So, in my tanks with CO2 I use 75% RO and 25% carbon filtered tap water to achieve a KH of about 5. Perfect IME.

About Rubbermaid tubs:
I forgot they made food grade tubs. I think the food grade ones would work great! The ones I saw on the link in the other post were the cheap ones we find locally, which is what I used. I have done a little research recently and come to this conclusion. The tubs should be just fine for temporary use, a couple weeks to a month or two. The longer they sit full of water, the more they start to leach. I talked to a guy that used a kiddie pool and rubbermaid tubs and ended up losing a lot of fish before he figured out the plastic was the issue. They were in use for over almost a year before he started to see fish death, poor plant growth much before that. So, in a reservior situation one would assume the tub would sit full of water for extended periods of time, making the plastic an issue.

Just what I think, and info I have gathered from my own experiences.

[RTR]

RO water only in theory is at 7.0, and that would only be likely with a very high rejection rate for maximum purity. It also will be very brief. Contact with atmospheric CO2 will drop the pH of RO very rapidly. You should expect any RO or DI in a reservoir to test very acid.

[DIYMatt]

Thanks Slipknottin! That is good to know. On my first run of the reservoir my RO tested just about 7.0. I didn't test for ph again until I drank some of the water from my resevoir months later. It tasted plasticy, so I testedthe ph at 6.2. I read up on Rubbermaid tubs and figured the plastic was the issue. So, maybe it wasn't.

On testing the water out of my new setup, sure enough it is about 6.2 also. Hmmmm.......I should check my sources mor closely. Thanks again!