question about ro/di water procedure

[rjkim]

Hi ppl.
So I just got a 100gpd RO/Di machine to start making the water for my 100 gal marine tank..

my question is that how much ro/di water should i make and how much tap water can i use in my tank? or perhaps all 100 gallons should be ro/di water? the machine makes about 5 gallons per hour and wastes 4 gallons to every gallon made. I do not want to keep the water running all day to make 100 gallons. can i mix the sea salt with 1/2 ro/di water and half tap water to have for my tank water, or does that defeat the purpose? also, I am getting a 100-gallon tank from a friend and plan to bottle up about 30 gallons of his salt water from the original tank. are there any problems with mixing the old tank water with the new water that i am making? lastly, what are some additives i should add to the ro/di water before I put it in the final tank? i plan to do a fishonly tank with live rock.

thanks for all the help and input.

rich

[Bajathree]

I would use all RO/DI water /ubbthreads/images/icons/wink.gifYou are defeating the purpose mixing it with tap. All you need to add is salt, for a FO tank I would not use any additives. The balance for RO/DI should be 3gal waste for every gal of finished product, your waste at 4 gal per is a little high. If this is a new set-up I would use no old tank water. If you are moving this set-up from your friends house to yours and setting it right up then using 30gal of old tank is fine.

[RWD]

I agree with Baja, new tank new water. Moving tank, old water+new rodi. I would not use tap water if rodi is available.

[rjkim]

Thanks for the input guys.. will do

Rich

[broadwave]

Just like Baja3 said, you are defeating the purpose of using an RO/DI system...you might as well just add all tap water /ubbthreads/images/icons/crazy.gif

I am not sure what type of RO/DI system you got (where you purchased). Anyway, the water pressuer in an RO membrane should be between 40 and 80PSI. If you are less than that you will produce more waste water. If youa re running at these PSI pressures then you have some REALLY BAD water!!!

If you are indeed less than 40 PSI i suggest you get an RO booster pump. You can get one here...
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=2005568601
They are $125 + shipping

This company has the BEST prices on RO/DI products and systems. He is also a class act to deal with quick turn around time on a "quality" product.
I bought my 6-stage 200gpd system from him for only $189!!!

This is it.... http://imagehost.auctionwatch.com/preview/aq/aquaee/200GPDSystem1.jpg

[kevinpo]

I would use some water from the old tank if you are going to set it up as soon as you move it (same day). There can be lots of beneficial plankton/micro organisms in the old water depending on the condition of the old tank (I would check for critters in the sandbed and good macro algae growth in the current setup). I would not use tap water.

JMO/IME,
Kevin

[rjkim]

for the ppl who have the di along with the ro system, read this

While in Kentucky at an Aquarium Club meeting (1995), an aquarist approached me with a problem. He had a reef tank that was having problems with pH bounces. He was adding a buffer for alkalinity. He was not overfeeding or overstocking. I asked him to get his source water tested. "Oh no problem", he said, "I use RODI". I suggested him try using just RO. A few months later he called and told me he had success with the removal of the DI. Great! but why did that help?

After testing several times on several aquariums, I found a possible reason for the success my colleague had with the removal of the DI. It seems that a Deionizer does in fact lower the pH of the water a little, but that shouldn't be a problem with the use of buffer. It seems with the deionization of the water molecules, the pH and/or alkalinity becomes unstable. No chemistry testing was involved, just trial and success.


I got this of an article on about.com. Anybody experience this?

Thanks
Rich

[Chuck S]

As a side note most times many suggest remineralizing RO/DI water since yes it will be base 7.0 neutral H2O

[rjkim]

can you explain remineralizing?
is it along the same lines as buffering the ph to @ 8.2?
thanks

[Chuck S]

basically bringing calcium and buffer back to the water through adding a powdered aragonite. Since DI removes good and bad things things from water it is simply a way of adding a balance back into the water. Aragamight is a brand name of one of these such products.

[broadwave]

[ QUOTE ]
After testing several times on several aquariums, I found a possible reason for the success my colleague had with the removal of the DI. It seems that a Deionizer does in fact lower the pH of the water a little, but that shouldn't be a problem with the use of buffer. It seems with the deionization of the water molecules, the pH and/or alkalinity becomes unstable. No chemistry testing was involved, just trial and success. <hr /></blockquote>

This is a very interesting statement. Before my RODI set-up I used just DI with KATI &amp; ANI my PH is pretty stable at 8.36.
Maybe my KATI &amp; ANI didn't work too well???

[Unresistible Blue]

One of the baseline features of the use of RO/DI is that it gives you a consistant water quality. You can add supplements as desired/needed. The quality and constituents in tap water, and some will argue well water as well, vary and therefore complicate water quality management.

Blue