RODI water and large freshwater systems

[weedmonger]

I am in the planning stages of a large (3000 gallon plus) freshwater river tank. The tank will house large and small river fish like gars, catfish, bass, crappie, ect.

I don't really see the tank have much in the way of plants.
If I integrate the use of RO or RODI water for top offs and water changes how much will I have to worry about pH control or mineral depletion and such?

How can I go about handling this depletion on a large scale?

I'm not real excited about the idea of using stright tap water...not that our tap water is really that bad.

 

[Venom SS]

I am in the planning stages of a large (3000 gallon plus) freshwater river tank. The tank will house large and small river fish like gars, catfish, bass, crappie, ect.

I don't really see the tank have much in the way of plants.
If I integrate the use of RO or RODI water for top offs and water changes how much will I have to worry about pH control or mineral depletion and such?

How can I go about handling this depletion on a large scale?

I'm not real excited about the idea of using stright tap water...not that our tap water is really that bad.

I did alot of research when I got my big tank and was on the verge of buying a RODI system and decided against it. Those systems strip the water completely of minerals. RO systems are better for saltwater tanks, where heavy minerals can adversly affect inverts and you would be adding and mixing your own salts and trace elements back into the water to maintain proper balance. If your tap water isnt really all that bad, invest in gallons of Prime lol. I thought my wild caught south american fish wouldnt respond well to conditioned tap water, but they took to it without ever missing a beat. They went from super soft bottled spring water to fairly hard tapwater. Prime is good stuff.

 

[hmt321]

you can set up a drip system using under sink charcoal filters for very little
in the garden section of lowes or HD you can find drip emitters of various GPH

if you set up 3 - 2gph drip emitters that would change approximately 1000, gal per week, the cartridges i use are good for about 2000 gal of water so you may want to add a second filter, run them in series, then only change one per month

 

[kzimmerman]

I wouldn't bother. Unless your water is pretty bad, I would just use it. You could have pretty serious pH complications, and on the whole its just not necessary.

 

[Noto]

+1. Unless you have really awful tap water or very sensitive fish (which the ones you mention are not), dechlorinated tap water will be just fine. If you use RO/DI you will need to reconstitute it with some sort of mineral mix.

 

[weedmonger]

Thanks for the ideas everyone and keep them coming...

from what I am seeing so far I should be using filtered of RODI for top offs but not for waterchanges. Water changes should just be conditioned tap water.

My understanding is that these fish are mostly pretty hardy. Does anyone know of an optimal temperture or water chemistry for this tank.

Or should I just take some river water measurements on my own and stop worrying about it so much?

 

[kzimmerman]

These fish will adapt to pretty much any water parameters. If you give us a specific list of the types of fish your after, we could help out much more. My fish are living in hard water with a pH of 8.0, and have breeding colors. The pH of where they came from was 6.5. Don't worry so much, I even have tetras living in this water, and they are doing great. Unless your trying to breed a sensative fish, don't worry.

 

[Buckeye Field Supply]

If what you are after is dechlorinated tap water (rather than pure [RO] or ultrapure [RODI] water), then a simple 2 stage filter would be a good low cost approach.
First Stage: Sediment filter
Second Stage: Carbon block (not GAC)

If you are thinking about flow rates under 1 gallon per minute, then a using 10" x 2.5" filters would likely be ok. I'd need more details to say for sure.

One other thing - check with your water utility to see what they use as a disinfectant - chlorine or chloramine.

Russ

 

[mdblo3]

If the water has chlorine (not chloramine), is it not possible to simply use a conditioning tank with air stones or water pump to circulate the water and allow the chlorine to evaporate prior to using it, thus avoiding the cost and hassle of using Prime or other treatments?

 

[Spiritofthesoul]

If the water has chlorine (not chloramine), is it not possible to simply use a conditioning tank with air stones or water pump to circulate the water and allow the chlorine to evaporate prior to using it, thus avoiding the cost and hassle of using Prime or other treatments?

Yes, but prime is way much better!

To OP, just go with the tap+prime combo. RO water's pH is highly unstable as all the buffering agents have been wiped away