Distilled for top off but tap for water change

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I used tap when i started my tank and it led to a bad cyano outbreak and the algae problem. I bought a ro/di unit and do my weekly water changes with it snd my algae problems are diminishing. After seeing the ro filters i wont even drink my rap water lol.
 
I'm currently using tap and I'm not having any algae problems except some cyano on one side of the tank. It's very minimal and I'm pretty sure it's because of flow. Either way, I am going to invest into an RO/DI system soon and will begin buying RO water since my tank is destined to be a reef.
 
Even your buying outside destilled or rodi, you still need a tds meter to check it, those filters never get changed when they are needed, you really have no control over your reef water when using someone else's, as you do not know when filters are changed (if ever) :)
 
Even your buying outside destilled or rodi, you still need a tds meter to check it, those filters never get changed when they are needed, you really have no control over your reef water when using someone else's, as you do not know when filters are changed (if ever) :)

Still better than using tap though, right?
 
Since I don't have any meaningful coral yet, I figure this was my chance to try this out and get at my nitrates.

For the last 10 days I have changed 10% daily of my tank water with tap water mixed with reef crystals. The goal was also to slowly raise my salinity.

My nitrates went from 20-30 to about 10 ppm! My tank also looks a lot cleaner from all the dirt I siphoned out.

All the livestock seems to be loving it.

I know it would have been even better to use ro/di, but instead of procrastinating over my RO/DI unit I acted and got my tank cleaner.

Also it is a good habit now. It's kind of a ritual now, if I don't change my water daily I feel bad.;)

I still top off with distilled water. I'll keep you posted on the incoming disaster. ;)
 
One of the problems with tap water is that it can contain things that most kits don't test for. If you test the TDS (Total Disolved Solids), they will be much, much higher than RO or RODI water. Those can cause problems over time.

If you are going to use tap for water changes, then what is the benefit to using better water for top-offs? I would go the other way if I had to. At least the big water changes are putting in good water.

I've been handling the water in my tank this way for 7 months so far. The only problem that I've seen from this is that there is an occasional minor diatom outbreak occasionally but its soo minor that it can hardly be considered an outbreak. I will add that I have excellent tap water in my town though.
 
Tap water breaks a rule I use, don't add it unless you can test for it. There are many things that can appear in tap water that would take a serious testing machine to recognize and quantify. Most are unimportant, but some, such as trace metals can ruin your day. Might not see any metal until your city works on the water lines or associated equipment. Areas that flood also see major fluctuations in tap water quality. Evaporation effects concentrate these toxins in your tank over the long term, even with water exchanges. As a result, most if us believe RO/DI water is consistent and will keep you out of trouble even if your tap water tests good with the tests you have.
 
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I agree with using RO/DI water but playing devil's advocate here.

We are putting tap water in our own bodies over a long time.
Paying $100's per year for Aquafina/Dasani water ( RO water) and drink this and people
tell me it doesn't have enough minerals for our own body.

???????????????????:facepalm::facepalm::facepalm:
 
I agree with using RO/DI water but playing devil's advocate here. We are putting tap water in our own bodies over a long time. Paying $100's per year for Aquafina/Dasani water ( RO water) and drink this and people tell me it doesn't have enough minerals for our own body. ???????????????????:facepalm::facepalm::facepalm::facepalm:
Two very different scenarios. The human body can also concentrate metals, like mercury. Sea life also requires minerals that seawater supplies, but as with us, some chemicals are detrimental. Your kidneys constantly filter out toxins, just as your reef does, but some toxins don't filter out, they build up. Good discussion though.
 
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I work for a large water municipality. As mentioned the chemicals we use to purify water are ok for us humans but not for our reefs. Compounds with nitrates and ammonia and different metals are what is dangerous for our reefs and fish.
 
Don't want to bring out controversy, you are all correct.

But once you treat the water to precipitate heavy metals and make sure the water is free of phosphate or nitrate I believe it is ok, specially if those levels are high in your tank.

Anyway, Salt mixes are known to contains heavy metals contaminate order of magnitude higher than natural seawater.

I use reef crystals and on the bucket they say it is ok to use tap and the mix contains metal detoxifiers. I bet instant ocean guys know their stuff.

Of course test your water for nitrate before using.

Silicates and iron could also be an issue but a far as I know some people dose this stuff

Peace
 
Don't want to bring out controversy, you are all correct. But once you treat the water to precipitate heavy metals and make sure the water is free of phosphate or nitrate I believe it is ok, specially if those levels are high in your tank. Anyway, Salt mixes are known to contains heavy metals contaminate order of magnitude higher than natural seawater. I use reef crystals and on the bucket they say it is ok to use tap and the mix contains metal detoxifiers. I bet instant ocean guys know their stuff. Of course test your water for nitrate before using. Silicates and iron could also be an issue but a far as I know some people dose this stuff Peace
Just curious, what study mentioned mined salt mixes or even evaporative salt mixes contain more metal than the seawater they came from? I agree the the instant ocean guys are clever, but I don't necessarily agree with them in all cases. Some communities have water that no salt mix can cure. Since we all give information based on what we are told, I have no idea how good or bad their tap water really is. The default position is to use something that is quantifiable across all scenarios, recommending RO/DI water cannot get anyone into trouble and since you don't really know what is dissolved in your local water, starting with pure water makes sense to me. No controversy intended, but it is worth discussion.

I am unaware of anyone in SW that doses iron or silicates (which produce diatoms).
 
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I agree some tap water is not usable plain and simple. Also have a look at the municipal water report. My municipal water does not contain chloramines as well.

Here are a few links. :

General intro to water very good and he recommends against using tap. ;)

http://www.reefkeeping.com/issues/2007-03/rhf/

Salt mix study:

http://www.advancedaquarist.com/2005/11/aafeature1

Silica in aquarium:

http://www.advancedaquarist.com/2003/1/aafeature1

Iron in aquarium :

http://www.advancedaquarist.com/2002/8/chemistry
Those are very interesting readings
 
In scanning those articles, I didn't see a mention of high concentrations of metallic compounds other than magnesium. It does support Mr_X's use of any salt mix available and rotating them. Probably makes sure you are covering all the bases during water exchanges as the ionic balance of various elements changes from one salt mix to the other. I use Reef Crystals too and it has preformed fine for many years, as I dose the essential elements.
 
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Second link

I agree some iron is needed for plant growth, but nobody I know doses it above levels already present in the salt mix. Algae seems to grow fine on the regular levels in salt mixes.

Same with selenium, which is a source of silica and silica levels help promote diatom blooms. Nobody doses it to my knowledge. I try to eliminate it from the water.

I wish I had test gear like that used in labs and water treatment facilities. Then a clearer picture might be seen.
 
I took this to mean that almost all metals tested fell below the limits of the testing equipment: Many elements that were included in the ICPMS results were below the test's detection threshold of 0.5 ppb for all salt samples. Accordingly, these elements are not included in the data and comparisons below. These elements were: Beryllium, Scandium, Gallium, Germanium, Yttrium, Zirconium, Niobium, Ruthenium, Rhodium, Cadmium, Tin, Cesium, Lanthanum, Cerium, Praseodymium, Neodymium, Samarium, Europium, Gadolinium, Terbium, Dysprosium, Holmium, Erbium, Thulium, Ytterbium, Lutetium, Hafnium, Rhenium, Osmium, Iridium, Platinum, Thallium, Thorium, and Uranium. Silver and Tellurium were below the test's 5 ppb detection limit for all salts. Interestingly, Silver levels for Instant Ocean and Coralife were reported at 248 ppb and 410 ppb respectively in the 1999 Atkinson and Bingman study. Gold and Mercury were below their 50 ppb detection limit, and Iron was below the 500 ppb detection limit for all samples. The tests for several elements showed little significant difference between salt mixes. The data for these elements can be found in the Appendix.

The evidence over the years IMO is that there are no commercial salt mixes that are lethal to any aquarium life.
 
I never implied that any salt mix is toxic.

I only pointed that many studies have found some metal levels order of magnitude higher compared to sea water. It does not mean that those levels are toxic.

As it is explained in the first article we should not put too much weight to those detailed analysis as there are too many variables. We should stick with brands that are time tested.

The point I'm trying to get across is that treated tap water is also in most cases not toxic.

As I have explained in the thread earlier, topping off with anything else than to/DI or distilled is a bad practice because of concentration of pollutants over time.

But IMO tap water is acceptable for water change if its nitrate and phosphate are significantly lower than your tank.

You might say : why bother with this debate if you need pure water for top off anyway?

I see no big hassle in handling one 5 gallon jug weekly to the store close by. But carrying more water than that did not get done for me.

I would also love to have this expansive test equipment to test a batch of saltwater with tap vs with RO/DI! ;).
 
Its worth the investment without a doubt. I wouldnt add the high tds tap water to a system at all, not top offs or water changes. Doing one and not the other is just silly, it makes no sense. If you go to the trouble of adding ro.di water for one thing and then add tap water for the other you are wasting your money on the ro/di water. :) You can get a cheap ro/di unit for about $90 on ebay that is portable and a great starter solution, I myself went that route until i was certain I was going to stay in the hobby, then invested in a $180 unit. There really is no way to get around it, tap water in the long run is just not good. If you are doing corals at all then its needed, if its fish only, well, some people dont care about the total dissolved solids they are introducing to the tank as its only fish. lol But if the end goal is to have coral then really really consider not using tap water.

I've been looking for such items at that price range and they seam to either have to be plumbed into the water line or shipping is insane .
If you happen to find one please let me know .
 
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