ro/di water vs. tap

[squishifishi]

what is the reason for using ro/di water in reef and salt water tanks? My pico has been running 3 weeks now on tapwater and the params are all fine:
ph-8.1
ammonia-0.15(not as bright yellow as 0, but not quite green either)
nitrite-0
nitrate-2(same deal, not near as dark as 5, but less bright than 0)

so, i'm guessing that using tap water is not a problem with parameters, but something else? either that or i have good tap water!
so, what IS the problem with tap water?
I let mine sit for a few days to dechlorinate too btw, so that's not an issue.

All that is in there now is a blue leg hermit, a mini brittle star, some hitchhicker white ball nems and a green stripe shroom. i'm waiting to add more.
so, do i need ro/di water, and why.
thank you all so much!

[fishchef]

Tap water is a problem just waiting. Most tap will have a TDS of 200-400 ppm. Lots of impurities such as phosphates, nitrates, lead, silicates, and many others we can't even guess at, to mention a few. Some cause issues with algae and some are toxic to your fish/corals, etc. You will get posts that say they've used tap for years. What's in the water you'll never really know. I had a system years ago using tap. My filtration pulled out the impurities, but when I did partials problems started. We had amenomies die for one thing. Its an important expense.

[squishifishi]

so, ro/di water is not something youeven hear about on the freshwater side... why is it such a major issue in sw but not fw?
will using water from my britta filter have the same efect?
thanks again!

[bertoni]

The Britta won't do much for cleaning up the water.

I don't know much about the freshwater side, but marine animals can be very sensitive to copper, zinc, and other metals. Even 5 ppb of copper can kill some invertebrates. Water companies sometimes add anti-corrosive agents to their water, and those can be very toxic, as well.

Most often, tap water is clean with respect to nutrients like phosphate and fixed nitrogen, but they are the the least of your worries.

[tmz]

Fish and people do ok with small amounts of metal;marine invetebrates do not.

[Handil]

If its city water, let it run for a min and then use a swimming pool chlorine test on the water and you'll see how much is really in there. I used to use dechlor tap in fresh water many years ago, but it still proved too much. It will depend on your city, but the chlorine can be so high. Also a big +1 to the other posters about the other chemicals present in tap water. We don't just use ro/di water because we like spending more money.

[squishifishi]

huh. i wonder why saltwater inverts are so much more sensitive. i always had crabs and shrimp for my fw tanks.(fiddler crab, red claw, ghost, amano, rainbow, etc.) i really like those much more than fish.
anyway, do you think the britta filter will do anything? I guess it's better than nothing while i wait to get some ro water. i can probs just get some from the grocery store.

[tmz]

Not much from the britta. I don't know why fresh water invertebrates are less sensitive to copper and zinc and other metals, probably evolutionary mutations and more exposure naturally.

[givinggoodwill]

you dont *need* rodi, but it's much better that way.

[tmz]

Some folks run reeef tanks without ro/di where local water supplies are very good but even then,there is a risk of impurities from pipes fittings ,etc.

[Tuton]

I used tap water in my first tank and trust me, algae will be a problem. Are you using API test kits (they are garbage), if not what is the brand name? If you live in an older home you could have copper pipes, which will also kill everything. This should clear most things up:
http://www.youtube.com/watch?v=3sCVQTHHw5M

[shifty51008]

I will disagree about api test kits being garbage, they have been shown to be very close to readings as some of the top name brands however they dont read in the low range areas as good as others.

[nystang]

If you don't want to spend $ on RO/DI system, you can use distilled water sold in gallons. I have used these for a couple of months before I switched to RO/DI. I didn't even think about using tap although my tap water has TDS 34 but heavy in sediments.

[Tuton]

Many LFS will sell or give away RO/DI water

[tmz]

Originally Posted by shifty51008

I will disagree about api test kits being garbage, they have been shown to be very close to readings as some of the top name brands however they dont read in the low range areas as good as others.

I also like api kits for ammonia, nitrate,nitirite and alkalinity. They cross check well with slaifert and others,ime.

[SGT_York]

Some areas the tap water is adequate and will work fine for a salt water aquarium. Most areas there is significant nitrate and phosphates like .7 ppm. which means calcium will not bond to coral and you will never control the algae. Copper pipes do not present a significant problem in most homes. I would not use tap water unless I tested it several times using reliable equipment. The major concern are the phosphates and nitrates.

API is fine for a softies tank but the color gradient is not accurate enough to ensure phosphates are below bonding levels. two lowest are .25 and 0 nothing inbetween and only a slight color difference from yellow green to yellow.

[animalkingdom]

Another thing to think about reef tank is they use a lot more light than any freshwater planted tank. This means any present nutrients can be used for algae growth a lot easier with the added light. Reef tank = proper parameters for algae heaven if nutrients are present.

[disc1]

Originally Posted by tmz

I don't know why fresh water invertebrates are less sensitive to copper and zinc and other metals, probably evolutionary mutations and more exposure naturally.

I think, and this is mostly conjecture but makes lots of sense, that it is evolutionary. Marine animals live in a pretty stable environment. The ocean is big and doesn't change much or very fast.

By comparison freshwater lakes and ponds and streams come in a wide range of water qualities. A pond with a little runoff can change chemistry pretty fast. Things can go in seasonal cycles as runoff brings things into the lake or pond and then summer dries it up and concentrates those things. Freshwater bodies are in a much more intimate contact with their terrestrial surroundings.

So in the end, if you are going to live in freshwater you'd better be adaptable as far as water chemistry is concerned where that isn't so necessary in marine environments.

[squishifishi]

ahh! i'm having an algae outbreak! i guess i'd better buy some water soon if that is causing it!