Water Changes still needed?

[broskie]

If I lose an average of 5 gallons a week do to evaporation and I am refilling with RO water and dosing CA and MA. Are water changes still necessary?

Water parameters
78 Degrees
1.024/.25 Salinity
PH 8.3
CA 420
MA 1320-1340
Po4 0
Ammonia 0
Nitrate 0
Nitrite 0-.25ppm
KH 11 "I beleive if this is the one that goes to 12"

 

[RBursek]

It depends, for a coral laden tank yes, because there are trace elements being used up and you want to keep your trates down, that only water changeing will do, Just adding evap replacement does not do that. If a fish tank you do not need to be very religious about water changes.

 

[Harry_Y]

Yes

Your corals will thank you

 

[Troylee]

definetly need to keep up water changes regardless of evap. by replacing the water your just keeping your salinity some what stable....as it evaps your salinity rises and so does your nutrient levels you dillute both with a top off but your not actually removing them if that makes sense...:)

 

[SaraB]

Absolutely, keep up the water changes!!! You'll be replacing the elements that the corals have used up in your exising saltwater and also be diluting your nutrient levels as troylee stated above. I replace between 4-5 gallons a day from evaporation and try to stay on top of weekly water changes.

 

[Nanoreefbro]

Great question I used to wonder the same thing as well...

 

[hollback]

I also agree that they are needed but I have a friend that hasn't done one on his 180 in a little over a year and it looks amazing.

 

[terryagi]

The "stuff" that you are removing via water changes is not removed by evaporation.

 

[LegoZ81]

There are disolved organics and waste that cannot be removed by skimming/carbon and even ozone. These will build up over time and can cause many problems. I had a freshwater planted tank that was always 0 on nitrAte and had all kinds of problems due to no water changes.
Also you replace trace minerals and help restore proper chemical balance with waterchanges. if you don't do them the chemical makeup will shift further and further away from what natural sea water is.

 

[beaslbob]

IMHO water changes will slow down but not prevent problems. So that problem with say no water changes that show up in 4-6 months may show up in 4-6 years with water changes.

After some time the tank winds up running so that the stuff in the tank just before a water change equals (the total change between water changes)/(fraction of the water changes) plus whatever is in the replacement water.

Say you are doing a 10% water change every 10 days and nitrates are increasing at 1ppm/day (total change 10ppm). The tank will wind up at 10/(1/10)=100ppm just before a water change.

So to me what is important is to balance out the tank so that things are not changing. With plant life like various algae/corals for nitrates, phosphates, carbon dioxide and the like and to dose the calcium/carbonate/magnesium the corals or corraline uses up.

All of that points out why may "old timers" like me and (and perhaps paul b) with tanks balanced out with macros or ATS systems do very litttle if any water changes.


Still just my .02


sorry Paul didn't mean to speak for ya.

Edit:

sorry I got my forums mixed up. Paul B posts on another forum.

FWIW he has a reef tank with a hudson bay biotops that has been in continuous operation for 40 years.

 

[HighlandReef]

from what i have read water evaporation dotn take out the bad stuff, leaves it behind, so still need water changes

 

[Paul_N]

I would say yes to start out but then you can find your own schedule. I am at 12 months with no water change and my tank hasn't looked better.

I agree with beaslbob's comment :"So to me what is important is to balance out the tank so that things are not changing. With plant life like various algae/corals for nitrates, phosphates, carbon dioxide and the like and to dose the calcium/carbonate/magnesium the corals or corraline uses up."

Also like troylee said my salinity starts dropping, which I add pre-mixed ro/di water periodically back in to keep it stable(1.024-1.026).

 

[rock_lobster]

you need to do water changes if you aren't testing and dosing for every element in natural saltwater.

 

[jvalentine]

i agree with everyone. It is necessary to keep trace elements and calcium levels good

 

[lazyreefer]

Well, what about filling up an ATO reservoir with SW rather than just RO ?? I would assume that doing that say once a month should add enough trace elements and keep salinity in check. (depending on your reservoir and tank size of course)

I don't really see how the removal of 20% of your water once a month is going to remove a bunch of harmful stuff, the removal of 20% is only gonna remove 20% of the bad stuff. The addition of 20% of fresh SW once a month is only gonna dilute the bad stuff by 20% .

Now I have a 175 system and a 55 system and a 40 qt which is constantly running. The 175 I probably am doing too many WCs at one every 3 weeks. My numbers just don't change - for example I have never seen any nitrates with Salifert and API test kits. The salt I was using has less Ca, Mag, and Alk than what I'm shooting for so its costing me some coin in additives. (I'm changing asap)

On the other hand my 55 is a serious pain in the butt and I can't keep nitrates down. I'm doing bi weekly WCs with a very light load and I'm gonna go to weekly changes in an attempt to keep things steady. (I'm lazy and I don't pay as much attention to that tank - my fault)

My QT hasn't had a WC in a looong time, but it doesn't have anything but some corals and liverock and its numbers never change either with the exception of salinity. (I do top it off with RO) So, its obvious to me that I am my tanks own worse enemy by what I am doing to it, or not doing to it which ever the case may be. Obviously, the more water you have the easier it is to "maintain", although if it goes south its tough to get back under control and its costlier to dose. I don't know how these Nano guys and gals keep on top of stuff with tanks less than 30 or 10 gallons in some cases.....

 

[fab1971]

I used to do a water change every 2-3 weeks. I run a skimmer, have plenty of circulation and 2 filters. I went 3 months without doing any water changes. My corals suffered and algae started getting out of control. I now change the water every week. Tank and corals have never looked better. It definitely makes a difference. Especially in small systems like mine.

 

[beaslbob]

you need to do water changes if you aren't testing and dosing for every element in natural saltwater.

And if you can do a 100% water change with perfect water never incorrectly mixed up every day you will be fine.

But it is so easy to say water changes replace trace element, bad stuff is left behind etc etc etc.

But even with water changes that are convienent to hobbiests we still need to dose calcium, carbonates, and magensium.

Which means those things we can not measure are being depleted or accumulating also.

so unless you can pump non polluted ocean water through your tank every day, the only option is to have a balanced out tank.

To me relying on water changes is a sure sign something is amiss in the tank's operation. Which can not be corrected by water changes.


my .02

 

[Troylee]

Toping off with saltwater will raise your salinty not a wise choice for replenshing elements..For got the posters name sorry page before it was asked..

 

[beaslbob]

...
(and perhaps paul b)

...





sorry Paul didn't mean to speak for ya.

FWIW I got my forums mixed up.

Paul B posts on another forum and has a hudson bay biotope reef tank that has been continuous operation for 40 years. If anyone is interested you can google to see his tank.

Sorry.

 

[BlazinNano]

. I don't know how these Nano guys and gals keep on top of stuff with tanks less than 30 or 10 gallons in some cases.....

I hae a 28 gallon AIO tank that has been setup for a year now, well I have owned it for a year has been tanken down twice and moved. I do weekly 4-5 gallon water changes. I do them just to make sure everything stays in check because it is a small tank and one little thing makes a huge deal. I will admit for about the past 5 months I was lazy and did a water change ever of 5 gallons every month. For the past month I got my but in gear and kept up with the tank. In only a month I have noticed a difference in how the tank looks. Water changes are very important IMO.