Can I do to much water change?

Uslanja

Uslanja

Active Member
Hi everyone! We have low alk and calcium. We started to do 25% water changes. Is there a potential for us to do water changes to close together or to high of a volume and have some type of negative effect? We use Reef Crystals.

Parameters

Temp. 75.3
Salinity 35
Spec. Grav. 1.026
Ammonia 0
Nitrite 0
Nitrate 0
Phosphate 0
Ph 7.8
Alkalinity 5.6 dKH
Calcium 320
Magnesium 1380
 
QuentinB

QuentinB

Member
Hey guys, I'm probably not much help here, but I've heard a couple different thoughts on the matter. One being that too much water at a time can upset the balance of everything, and possibly kick off a mini-cycle or something? I don't know, though I will say that I've moved my FW tank twice now, resulting in pretty much total water replacement, and never noticed a cycle afterwards. SW could be a totally different story though.

The second thing I've heard is that very little bacteria actually lives in the water column, and the amount of water changed shouldn't matter in that regard. Which makes sense in my head, I guess.

Honestly, I don't want to steer you in the wrong direction though, so hopefully someone who knows what they're talking about stops in here!
 
glampka

glampka

Active Member
The only way you can do too much of a water change & have it be harmful is if the pH, salinity & temperature of the new water are way different than what is in your tank. You'll stress everything. Quentin is correct in saying that most of the bacteria does not live in the water column. It's attached to the live rock & sand.
 
GlassMunky

GlassMunky

Active Member
I've done over 50% changes on my 14G nano and never noticed a problem. as long as the new water is close to the old in temp, PH, and whatnot.
 
Uslanja

Uslanja

Active Member
Hi Quentin and Gary! The temp, salinity are a match. The Ph is fairly close to each other, I think, but the alk and calcium will be different. I have no idea what would be a significant difference though. Any idea how much of a variance would be acceptable between Ph, alk and calcium?
 
Uslanja

Uslanja

Active Member
Hi GalssMunky! We posted just about the same time and I didn't see your response. My thought was 25% water changes every 4 hours or so might be similar to an acclimation rate and avoid any serious shock. But I'm not really sure.
 
jpsika08

jpsika08

Well-Known Member
I think the only downside of doing huge water changes is that you remove beneficial bacteria from the water column, if you are having trouble with Alk and Ca probably the best way is to dose every week on a timely basis, with my tank even that I do 15% WWC the Alk and Ca tend to lower each time, so I dose until levels are met.

And yes, your Ca and Alk are really low, I use Kent Tech A and B which are Ca and Alk, really good.

Here is a neat Chemistry calculator so you know how much dosing you need to increase the levels: Reef Chemistry Calculator
 
Uslanja

Uslanja

Active Member
Hi Juan! We have been trying to address the calc and alk with B-Ionic 2 part but it hasn't had an effect. The levels are still dropping and fairly quickly.
 
PSU4ME

PSU4ME

JoePa lives on!!!
Staff member
PREMIUM
Have you thought of switching salt brands? I have "heard" that RC can be off a little thus you could not be getting what you need. I "just" purchased Tropic Marine Pro Reef.....hoping to see more consistency in the levels.

just a thought.
 
D

DaveK

Well-Known Member
More to the point, before you start doing big water changes, measure the calcium and alkalinity of the newly mixed water. If you are not getting good reading from the new water, water changes will not do you much good.

In this case I'd recommend a better quality salt that mixes close to ideal.
 
glampka

glampka

Active Member
Dave,
What container did you buy - bag, pail? Mix up the dry salt real good. Some of the ingredients may have setlled to the lower part of the container if they have a smaller particle size. Also, what is the pH of your water before adding the salt mix?
 
Uslanja

Uslanja

Active Member
I have another batch of water cooking. I'll check the parameters as soon as the salinity is correct. In the mean time I have checked the water in the tank to see what effects the change has done;

Ph 8.1 increased from 7.8
Alk 6.1 increased from 5.6
Calcium 340 increased from 320

It has changed the parameters in the correct direction.
 
Uslanja

Uslanja

Active Member
Hi Gary! Can I test the Ph of my base water with the salt water test kit? We always buy Reef Crystals in the pail. But we have noticed that although we consistently measure the amount of Reef Crystals that we add to a consistently measured amount of water our salinity will vary greatly. I assume this could apply to the other ingredients in the Reef Crystal mix as well. The test results on a new mixed batch of water are;

Salinity 35
Ph 8.1
Alk 16.0
Calcium 460

So, if I guess correct, 4 more 25% water changes will max the Ph at 8.1 and will likely achieve an Alk level of 8.1 with a calcium level of 400 if levels rise constant based on the above results. Or am I way out to lunch on that one?
 
Uslanja

Uslanja

Active Member
Hi Juan! We are using Salifert for the Alk, Ph and Magnesium, API for the Calcium, Ammonia, Nitrite and Nitrate. The test kit just started to change colour as we finished putting the last of the reagent from the 1 ml syringe in to the sample.
 
Uslanja

Uslanja

Active Member
Hi Glenn! The Ph isn't a big concern to us because we understand that alkalinity is more important. We further understand that Alk and Ph have some type of relationship and if Alk is good then Ph should be also. But after saying all that, we are very much in a learning curve here. We do test Ph as a matter of routine. We really do not understand what would cause our Alk and Calc to drop so much. Not much new in the tank other than some palys we moved over from our other tank. In an attempt to increase the Alk I did dose with part 1 of the B-ionic and not having an understanding of what I was doing I may have caused this. We were reading Dr. Randy Holmes-Farley's article "Solving Calcium and Alkalinity Problems" and that is where we read that water changes could be a good way to get things back into balance.
 
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