How to use RO

[titansfever83]

I've never used an RO system before so a quick run through would be appreciated.

My water is very hard, around 11 dGH. I'm wanting to get it down to at least 6 dGH. When I do my first WC (50%) with only RO water then it should lower roughly to about 5 or 6 right? And will that affect the fish with such a sudden drop?

What about the next WC? Should it consist of 1/2 and 1/2 of RO and tap water?

And please let me know the best system to purchase, you know, price, ease of use, cheapest replacement filters. Just want to get it right the first time. The good Lord knows how much I spend on the hobby already so a little advice would be appreciated.

Thanks
Jamie

 

[Dr Joe]

Never make that drastic of a change like that with fish in the tank!

OK, now that I've said that:

How big is the tank?

What kind of fish?

How long have they been in this water?

And why do you want to change it? (the first answer may answer this one too).

You'll have to balance reliability vs cost on these units, I found a cheap one with cheap filters once, first filter lasted a month while all the others lasted a week...so I'm thinking they put one good filter in the unit and by the time you go thru three other filters. as in my case, the company was gone. (I did find out they sold a large quantity overseas some where before disappearing, don't know where they were manufactured).

Where's Wolf3101 we could use his input here.

Dr Joe

.

 

[titansfever83]

1. How big is the tank?

2. What kind of fish?

3. How long have they been in this water?

4. And why do you want to change it? (the first answer may answer this one too).


1. More than one tank but I'm gonna experiment with my 55 gal first.

2. Geophagus 'Balzani'

3. approx. 2 months

4. I am getting (2) breeding pairs of Geo Tapajos 'Orangeheads' in next week. The 'Balzani' are being moved to my 75 and the 55 will only have the 2 breeding pairs in it when they come in.

 

[Bderick67]

I use RO, but only with my discus tanks. I do not use straigh RO, I use a mix of 70% RO and 30% tap water. You'll have to do experiments with yours to get the params you want. I would do more smaller water changes with the RO water to get the levels in your tank lowered. With RO water, not only will the GH and KH drop but so will pH and large pH swings can be very bad for your fish.

 

[Potts050]

I agree. the danger of keeping fish in very soft water outweigh the benefits in my opinion. If you want acid water its easiest to make with RO to start with but you need to buffer it with the right blend of tanic and humic acids to avoid pH swings.

A swing in pH can pooch your nitrogen cycle very quickly...

 

[titansfever83]

I use Seachems Neutral regulator for the ph. Works good for me but I'm gonna start mixing it with the acid buffer to get my ph around 6.6. Anyway, what RO systems do you guys have?

pros?

cons?

and do you add anything back into the RO water? I am trying Seachems SA Cichlid Trace with my WCs now but haven't seen a difference with the fish.

 

[tapeworm]

I use and RO for all my tanks, because the water coming from my tap reads at 40ppm up nitrates, and the water is hard. I have a Kent Deluxe Maxxima 60gpd unit. I always have it on, and I have set up a float on a 275 gallon purge tank, so when I'm doing a water change, and the water goes below the threshold, it starts making more water. I use Kent's RO right to replace trace elements, and Kents AF Cichlid buffer to raise the alkalinity of the water as well as pH. Add whatever you need to get the water to your specs, its been working great.

Below are links to the two products, I mentioned.

http://www.kentmarine.com/freshwater/conditioners/ro-right.htm
http://www.kentmarine.com/freshwater/cichlids/cichlid-buffer.htm

What I have noticed before I switched my fish over to RO water that I had made, was that I made the change gradual. Do a water change or two throughout the week of 15-20% you don't want to do something like 50+ and shock the fish. (different alkalinity, pH, etc)

 

[Wolf3101]

The Kent marine additive is a good product. All I use to buffer the water however is crushed coral in the bottom along with the substrait. I run all of our tanks at a 7.6 PH so you might have to experiment a bit your the way you want them.

The more prefilter stages your RO or RO/DI system has the longer the life of and the more efficiant your RO membrane is going to be. In our system I use a series of 6 progressivly finer prefilters from 10 microns to a half micron...a couple of them carbon impregnated. This might seem excessive but I have an output of 350 gallons per day and I produce about the same amount of waste water as RO/DI water. The normal ratio is MUCH higher.

I included a picture below of a good quality RO/DI system that will produce 50 to 75 gallons per day. My only objection to the system is that the canisters are NOT transperant.

The only filter cartrages I change very often are the first two stages. (least expencive by the way at about 12.00 a 4 pack.) The finer cartrages last about a year...the carbon impregnated ones last about 6 months...The DI resin needs to be recharged/changed every 6 months or so as well. The life of the RO membrane itself will depend on the prefilter and of course your water but figure on replacing it AT LEAST every other year.

I use RO/DI water directly in my tanks but like the Doc's already told you...you don't want to be making any sudden changes. Make sure that you pick up a good TDS meter and use it often. A TDS meter wont tell you exactly is IN your water but it will provide a good guage of whats going on.

True RO/DI water is between 0 and 5 ppm Total Desolved Solids. 500 is the maximum allowable for tap water. Your looking for a target mark of about 200 to 350 for most healthy aquariums.

I built our RO/DI system myself out of parts available on Ebay. It's really not too difficult once you get the hang of it. Almost all of the manufacturers use the same componants no mater whos name is on the system so I wouldn't worry about that too much but there are things you should look for.

Get the highest GPH membrane you can afford...
Use AT LEAST 3 prefilter stages to extend the membrane life...
You'll need a minimum of 45 to 55 pounds per square inch of water pressureon your supply line. If not you'll need a booster pump to increase pressure....
RO alone will get your water down to about 35 to 65 TDS...The DI componant brings it down the rest of the way if you need it....
Color coded lines can be a real lifesaver so stay away from systems with all white tubing...
Make sure to add a pressure guage if the unit dosn't come with one. This will tell you when it's time to change the filter cartrages and the membrane...

Thats all off the top of my head...feel free to PM me with any other questions.

 

[loach43]

Please elaborate on your DI canister. I would like to add one to my existing ro unit. Looks like yours is a "non-cartridge type" (?).

 

[Wolf3101]

Actully the one in the pictures is our old unit that I sold a few months ago. Those DI cartrages are refillable but not as effective as the three larger 10" units we have now. They do work however and are very inexpencive to add on to an existing system. They are possitioned in-line on the output from the RO stage.