Water Changes

[MitchM]

Yeah, that's what the majority of people believe. That they are necessary. I'm trying to figure out why.

We spend many agonizing weeks waiting for our newly set-up tanks to "cycle", allowing the bacterial populations to build up and equalize, then we drain it out and replace it with sterile water, which throws the bacteria balance out of whack again, and if the water changes are too large or too frequent, the tank could possibly mini-cycle, causing an ammonia spike.

When you think about all the biological processes going on in our tanks....feeding, excretion, all the messy business involved with reproduction.... ......even I feel better giving my tank some new clean water. But I don't think that I would call it necessary. There's bacteria and different critters to look after all that stuff. I would think that it's more important to obtain a balanced system that pretty much looks after itself.

I'm playing devils' advocate here because I don't like carte blanche statements like "water changes are necessary". If they're necessary, then why, specifically, are they necessary?...and what possible imbalances in our systems could we be covering up?

Mitch

Most of my holding tanks and personal tanks have large skimmers to handle high bioloads. Some reef tanks have ca reactors. When I do water changes, I dont have all day as I have many tanks, I mix the salt, let it clear, and dump it in. Ive never had any bad side effects from doing so. And I never do very large water changes.

I recently took apart a personal tank that I had setup and left the same for 3 years. It was a 77gallon Hagen, undrilled. It had 2 Hagen 802 powerheads, 1 Fluval 404 canister filter with bio material in it only, 1 tronic 200W heater, a 3"deep fine argonite subtrate, 120lbs of live rock from all different locales. Livestock was a Blue Regal Tang, a Heteractis Magnifica with 2 Goldstripe Maroon Clowns, a Flameangel, 2 Cleaner Shrimp, 1 Hawiian Cleaner Wrase. It had about 50 blue leg and scarlet hermits and 25 nasarius, 25 astrea, 10 turbo, 10 mexican, 3 trochus, 3 money cowrie, 1 carribean hairy reef hermit. There were many different macro algaes growing from the rock and subtrate, there was 1 green frogspawn, 1 green bubble, 1 devils hand, 1 fiji gold mushroom, 1 green open brain, 1 long tentacle plate, 1 sun coral, 1 purple goniapora, 1 alveapora, a dozen blue mushrooms, a dozen red mushrooms, a handfull of ricordia, and 1 pink birdsnest. The tank was lit with 1 IceCap 660 ballast overdriving 2 Philips 03Atinic and 2 Vita Lites. I changed the bulbs once a year for 3 years. I would say that I added no more than 4 cups of instant ocean saltmix to the tank in 3 years. I had a large bucket on top of the canopy that had aged tapwater in it, it was on a float valve to keep the tank topped up from evaporation, I would add fresh tap water to the bucket every week or so. The only food that I ever put in the tank was frozen and freze dried Mysis shrimp, sometimes supplemented with selcon. For the corals and macro algae I used Salifert all in one coral grower, and salifert iodine. I added the salifert every 2-3 weeks. I never cleaned the fluval once, the powerheads were always on, the lights were on for 12hours a day. There was no protien skimmer and the water parameters were always in the excellent range!
I would say that this was a very simple setup, but it worked well and required almost no maintence. I only added a half cup of salt to the tank a few times in 3 years due to saltcreep. The tank looked beautiful and everything was very healthy, all specimens are still healthy in other tanks. I wont recommend that everyone try this but It did work for me.
With proper balance a simple setup can easily maintain a healthy reef.
Of course all my current tanks have all the bells and whistles, mostly due to the fact that I move too many livestock in my tanks and cannot maintain balance in bioloads so I skim them like theres no tomorrow

[Aquattro]

Originally Posted by Carpentersreef

We spend many agonizing weeks waiting for our newly set-up tanks to "cycle", allowing the bacterial populations to build up and equalize, then we drain it out and replace it with sterile water, which throws the bacteria balance out of whack again, and if the water changes are too large or too frequent, the tank could possibly mini-cycle, causing an ammonia spike.

Mitch, I can't answer your question with any proof, but as a side note, the amount of bacteria in the water column is insignificant with regards to the N cycle. All the bacteria you need are in and on the surfaces present in the system. I can do a 100% water change and not get a NH3 spike.

[MitchM]

Originally Posted by reef_raf

I can do a 100% water change and not get a NH3 spike.

I don't agree, Brad. I would think that such a large water change would significantly change the water chemistry and PH to the degree that it would kill off a large number of organisms, resulting in an ammonia spike and resulting bacteria level swings.

Mitch

[Aquattro]

Mitch, I'm making the assumption that temp and pH are matched. And I'm directing the comment towards the bacteria count in the water column, not chemical considerations(although I stand by my statement).
While changing over tanks, I increased total volume from 60g to 160g (added 100g of seawater mixed that morning)AND I moved the sandbed. I tested for NH3 for 1 week following and did not detect any ammonia in the system.
This is tracking a bit off topic for this thread, so we can continue in a new thread if you like

[MitchM]

Originally Posted by reef_raf

This is tracking a bit off topic for this thread, so we can continue in a new thread if you like

Yeah, we're kinda out of the newbie zone......

I just don't want newbies to think that keeping a reef is more or less a glorified goldfish in a bowl. Water changes in in a goldfish bowl are necessary, but there's much more to reefkeeping than that.
Saying that water changes for a reef are necessary is an over-simplification.

We should probably be emphasizing keeping a low bioload to start.

Very important.

Mitch

(I'm in the process of taking down my house christmas lights right now, so I better continue that. It's very important too.)

[EmilyB]

I do 20% water changes bi-weekly, have for four years now.

The water change is an important tool for a newbie. It can be an immediate source of aid in some cases.

The last article Mitch linked to specifically mentions water changes as necessary to correct ionic imbalances that cannot be corrected otherwise.

When messing with Ca and Alk, many newbies tend to start adding one sided supplements and throw off their Ca/Alk balance badly. Water changes are the way to remedy this and then proper supplementation can begin. More can be found in Craig Bingman's articles.

I will also quote a comment he (Craig Bingman) made (googlegroups):

"There are still some old hands who pride themself in having never done a
water exchange on their systems, or for having gone N years without
having done a water exchange. I've looked at the chemistry of some of
these systems. While some of them are OK, others are way out of whack.
The usual response to that is that "stability must be more important than
aabsolute concentrations." To a degree, there is truth to that, but
given advances in water purification technology, salt mixes, etc, there
isn't any real reason why doing a water exchange should be destabilizing
anymore. Doing a partial on these systems that have badly drifted over
time might be a bit of a shock to the residents, but man, it must be one
*hell* of a shock for an organism coming into that system. And if a
series of modest partial water exchanges had been done over time, the
system would have been stable, and it wouldn't have drifted that far from
normal seawater chemistry."

--end quote

IMO, the water change is one of the VERY most important aspects to be aware of, whether you keep it in your back pocket for when you feel you need it, or look at it as preventative maintenance. No two reefing situations are identical.

[Beverly]

Originally Posted by Carpentersreef

Water changes in in a goldfish bowl are necessary, but there's much more to reefkeeping than that.
Saying that water changes for a reef are necessary is an over-simplification.

We should probably be emphasizing keeping a low bioload to start.

Very important.

Yeah, a low bioload is very important for not doing frequent water changes. But almost nobody keeps a low bioload once they've been reefkeeping for awhile, so let's be realistic here.

I know the syndrome all too well as I've done it and have observed many other people do it too. Gotta get this coral, and that school of fish to go with that lovely tang I saw at the lfs, oh, and I should upgrade the light so I can keep all these other corals. Pretty soon, your corals have to be fragged because they've grown so much. And the tank is still having water changes for a relatively low biolad tank when strange sh*t starts to happen like cyano all over the place, corals not opening, etc.

If a person does have a calcium reactor, a low bioload and many other positive factors indicating less frequent water changes, that's fine for them. But not many of us have gone so high tech, so frequent, relatively small water changes are vital, imo, ime, ymmv.

Powerheads, mechanical filtration units, skimmers, and any other working part of a reef also needs frequent regular and maintenance. Doing so rids these devices of detritus and they simply run more smoothly. It's kinda like changing the oil in your car. If done infrequently, the car will not run as well and over the long term will suffer from your negligence.

I've got four vry low-tech, high light reefs running now. The three nanos are sub-tropical and the 42 gal hex is tropical. The nanos get a water change and filter/powerhead maintenance one day, then a couple of days later the 42 gets its work over. I like the rhythm of this weekly intimate maintenance contact with our reefs, it's sort of like eating supper EVERY night. The work is never put off until next month. Gawd, next month .... I can't imagine how poor my reefs would look if I let them go that long. And I'd feel really, really guilty about it too.

However, that's just me and that's what works to keep our four reefs in pretty good condition.

[Aquattro]

you eat supper EVERY night?? I gotta try that...

[Beverly]

Originally Posted by reef_raf

you eat supper EVERY night?? I gotta try that...

ROTFLMAO!

Yeah, and I usually cook the stuff too. Tonight we're having baked Altantic salmon, corn on the cob, carrots, and some great garlic dill pickles. Yummmmm

To change the topic even further, do other reefkeepers eat fish?