water chemistry

[netafish]

well Ive had my tank for about 9 months or so now and I havent done a whole lot to it (including any water changes) and everything is going great. I bought a nitrite test kit the other day and I just finished testing the nitrite and its at 0ppm. unfortunately this is the only test kit I have so far. The fish appear to be in excellent health, and corals are healthy and growing very rapidly. I am wondering if there is any toxics building up in my tank that can creep up on you. I feed 4 times per week and add calcium supplements for my corals. I would like to have as natural tank as I can possibly get and from what I understand if my water chemistry is safe then I do not require a water change. My tank specs below

90gallon running for about 2 1/2 years
MH VHO protein skimmer and powerhead for water circulation
hermit crabs (blue legged and scarlet)
chinese hat snails (hundreds probably)
other various snails
approx 100lbs LR
3" sandbed
purple/orange lobster
camel shrimp (that I never see)
yellow tang 5"
cinnamon clown 2"
lawnmower blennie
6"x6" maze brain
3"tall Xenia pulsing
2'x2' approx button polyps
4"x4" candycane coral
gold crown mushroom leather6"tall
small 1"> featherdusters all over the tank
thats about all I can think of right now

cheers

[billc]

Sounds like to me that things are working good for you .. My tank is only 6 months old and have been fighting a nasty cyno outbreak.. But if yours is 2 1/2 years old I would think don't change a thing.. JMHO

[mojoreef]

netafish sounds like u have had sucess, but for me I would not run a reef with out the proper test kits (just to scary being in the dark) Since your tank is and has already matured, ammonia, nitrite and nitrate kits might not be needed unless u run into problems. Do u measure PH or salinity??? they can be important. I would also suggest calcium and Alkalinity at the least. When you add your calcium buffer how do u determine how much to add??

mike

[Geoff]

Sounds like things are going great. I would suggest doing water changes a little more frequently though. The water changes are done to replace trace elements are are used up by the inhabitants. Water changes are not only used to reduce the Nitrate levels in the tank. How is your coraline algae doing? This is a good indicator on your ca levels. I would suggest all of the test kits suggested by mojoreef. I like to have a nitrate test kit around just to have a starting point to look at if things seem a little off.

G~

[tdwyatt]

Originally posted by netafish
I am wondering if there is any toxins building up in my tank that can creep up on you. I feed 4 times per week and add calcium supplements for my corals. I would like to have as natural tank as I can possibly get and from what I understand if my water chemistry is safe then I do not require a water change

Although your corals appear to be doing well, you might want to consider increasing your water change schedule to include about 10% on a monthly basis (if not every 2 weeks). The primary reason for this is that over time, supplementing Ca and Alk with 2 part additives gradually increases the proportion of sodium and Chloride, such that after a year or so without regular changes, Magnesium, sulfate, Fluorine, Bromine, Iodate, phosphate, Potassium, borate, and Strontium levels become quite skewed in their proportionality to Calcium, carbonate, bicarbonate, Sodium and Chlorine. This can become so pronounced that the mixture is no longer Artificial Seawater, but rather a mix of mostly Sodium and chloride salts. Most 2 part additives use primarily a combination of sodium bicarbonate and sodium carbonate in one jug, and CaCl2 in the other. The Calcium and carbonate parts are used up, leaving behind the sodium and chloride ions as a residual addition to the water column. In the open ocean, such issues are moot, as all the conservative elements of seawater are continually renewed from deep reserves in the deep ocean (upwelling, terrestrial runoff, etc.) or recycled as part of the elemental cycles of the ocean elements. In our closed systems though, this cannot occur, and as the other elements are either sinked or included in biomass, the continued addition of Sodium and Chloride makes these two elements become the predominant agents of the water column's specific gravity. Many corals can adapt, others cannot and perish. The biggest problem with such a system is when organisms that have adapted to these conditions are either moved to another wqater colum or the deficiencies of the water column in which they live are corrected too quickly: either of which will result in damaging or the death of the coral specimen if the deficiencies are severe enough. New specimen additions to such skewed water columns will take longer than usual to expand and begin to function normally under these conditions. About the only way to correct for this is to do regular changes to reestablish the proportionality of the conservative elements and remove the excess sodium and chloride. Craig (Bingman) has suggested that once a year, a large water change on the order of 50% may be needed to totally correct this gradual shift in proportionalities. If your system has not had water changes in a few years, I would not do large changes initially, but rather do several weeks of weekly changes of increasing percentages (i.e., 4% this week, 8% next week, 12% the next, 16%, etc., up to a final 50% change. This will gradually acclimatize your creatures to the new electrolyte balances and replace your missing trace elements as well. To see Craig's article, click here for Craig's computer simulations of Na and Cl accumulations. Although it may seem that your corals are doing well, they are surviving, whereas they could be thriving when provided with the optimum water parameters. If you're already doing this, heh, just ignore this post as the midnight ramblings of a caffeine-crazed reef lunatic...

Hope this helps explain the topic, lemmeno if this doesn't make sense.

[netafish]

Tdwyatt that all makes perfect sense, Im still getting the grasp of saltwater still. Not exactly what I wanted to hear, but Im not going to argue. as you made plenty of valid points. Basically I got the idea of running a self sustaining aquarium from a local pet shop which has a 20gallon (I think) fish only system with a hippo tang (oldest tang Ive ever seen) and the owner has the system set up in such a way that it is its own ecological system and has only done 2 water changes in the past 15 years (yup thats not a spelling mistake 2 water changes, 15 years) the only other thing he does is top up the tank and of course feed the tang (he has actually had marine biologists from the local college/university take a look at how the system is set up). Well anyways thanks again for the help guys and I guess Ill be doing water changes on Friday.

Cheers

[Alice]

It's not only what you add in with water changes, it's what you take out. Yes, we run skimmers, algae scrubbers, refugiums and have deep sand beds but I just can't believe they can remove everything that can slowly build up to toxic levels. I'm sure that someone can give a scientific breakdown, but for me, doing water changes, even once a month, makes sense.

Alice

[Mnemic]

This seems to be one of those times when Balance is the key.

I'd love to not have to do water changes on a regular basis, but tdwyatt did a excelent breakdown of why they are good to do.

In the end we really are creating a syntethic environment, while trying to use natural methods, as well as unnatrual methods (skimming for instance) to keep that environment stable.

I think regular water changes even in a well balanced Tank shouldn't hurt, but hey, we can all dream to have a perfect system

-Paul

[Doug1]

After participating in reef foprums for at least 4 yrs now, I have followed the trends and heard most of the gurus of the hobby. I have come to the conclusion that try as we might, no mater how elaborate a system we devise, acheiving a balance in an enclosed tank system is going to be near impossible to maintain without some artificial help along the way. Even the biggest home system you can envision has limitations at some point. A relatively small display tank along with a much larger support system, using combinations of the available thinging and technology may get close for a time, but most of us dont have anywhere near the volume of the open sea for dilution , etc.
The idea that a 20 gallon tank is self sustaining over a period of 15 causes alarm bells to go off, esp with a Hippo tang in it, mine grew to about 10" in my original 125 SW tank