Water changes vs. Dosing/Calcium reactor

[dantimdad]

Given the cost of calcium reactor setups (and filtration) for 1000+ gallon systems, would it not be better just to do auto water changes to deal with keeping calcium and alkalinity stable?

I have been pricing out the cost of running all manor of dosing methods and, it seems to me, if you can get a salt mix that hits your target numbers, then just changing out a certain amount of water a day would work and honestly cost far less in the long run. Not to mention that you can run on less filtration equipment if you are doing this as well. Win-win.

This would require that you test the pH, Calcium and Alk every couple of days until you can stabilize the numbers then at least weekly. But, in a commercial situation you should be testing that often anyway in my opinion.

Thoughts?

 

[rushbattle]

Given the cost of calcium reactor setups (and filtration) for 1000+ gallon systems, would it not be better just to do auto water changes to deal with keeping calcium and alkalinity stable?

I have been pricing out the cost of running all manor of dosing methods and, it seems to me, if you can get a salt mix that hits your target numbers, then just changing out a certain amount of water a day would work and honestly cost far less in the long run. Not to mention that you can run on less filtration equipment if you are doing this as well. Win-win.

This would require that you test the pH, Calcium and Alk every couple of days until you can stabilize the numbers then at least weekly. But, in a commercial situation you should be testing that often anyway in my opinion.

Thoughts?

Can you show your math? I think it will be orders of magnitude more expensive than a calcium reactor, not less. Maybe use hamzas calculator to deplete alk and do big water changes to replenish to see how much saltwater you will need. I think one water change will equal the calcium reactor media for about a year in cost. Water changes even with elevated calcium and alk will likely not result in target levels even with low demand.

The Many Methods for Supplementing Calcium and Alkalinity - REEFEDITION

There is no aspect of reef aquarium chemistry more important than calcium and alkalinity. Many of my previous articles have described various aspects of these systems in detail. In reading those articles, aquarists will note one pervasive theme: that maintaining appropriate levels of each are...

www.reefedition.com

Effect of Water Changes Calculator

Aquarium calculator; Estimate the effect of repeated water changes on the concentration of a given substance.

www.hamzasreef.com

 

[C. Eymann]

Given the cost of calcium reactor setups (and filtration) for 1000+ gallon systems, would it not be better just to do auto water changes to deal with keeping calcium and alkalinity stable?

I have been pricing out the cost of running all manor of dosing methods and, it seems to me, if you can get a salt mix that hits your target numbers, then just changing out a certain amount of water a day would work and honestly cost far less in the long run. Not to mention that you can run on less filtration equipment if you are doing this as well. Win-win.

This would require that you test the pH, Calcium and Alk every couple of days until you can stabilize the numbers then at least weekly. But, in a commercial situation you should be testing that often anyway in my opinion.

Thoughts?

Depends on the demand? also how long the tank is going to be up, if you add it up, lets say you change out 40gal a day in a 1000gal system, over 5 years that's going to add up in salt cost, also if you have a tank packed with coral you may not be able to keep up with demand.

I remember a fella that had a 240gal packed with large acro colonies that had his CalRx malfunction/go offline and he was seeing his DKH drop by .5 per hour!

If it's a 1000 gal system and you wanted long term cost effectiveness for mineral replacement, you will not beat a calcium reactor setup.


Just my .02

 

[dantimdad]

From the above referenced article:

Water Changes


The one thing going for water changes is that it is hard to screw them up chemically (aside from salinity, pH and temperature). The bad thing is that it is impossible to replace more than a small amount of lost calcium and alkalinity to an aquarium in this way. Some salt mixes are available with higher than natural seawater levels of calcium and alkalinity, so it may suffice for the very lowest demand aquaria, but it cannot keep up with alkalinity in a tank with rapidly growing coralline algae and/or hard corals unless the amount changed is on the order of 20-50% daily. Calcium is somewhat easier to maintain with water changes, since some salt mixes have quite excessive calcium levels (500+ ppm), but even that is not enough for most aquaria.



Thanks for posting the link.

I guess I will stick to my tried and true Kalkwasser and only add another source if demands jump up later on.

 

[dantimdad]

I will say that I will still do small daily water changes to help stability. It's been proven so often to help that I can't ignore it.

 

[pdxmonkeyboy]

There is absolutely no way replacing water would be cheaper or more effective.

My sps eat calcium and alk way to fast to replenish it.

It is basically a percentage game and you are loosinh on both ends. My calrx kicks out HIGHLY concentrated dose of minerals where as replacement water just contains the appropriate amounts.

This would mean that in high volume and high deman systems you would need to replace almost the entire system volume to keep things stable because if you were adding say..9.0 dkh water to a system with a dkh of 8.8, your total dkh is still dropping.

It costs like 10 cents a day to run a calcium reactor. A 2.5% water change on a 1000 gallon system would cost $15 dollars.

For small, non sps sytems auto changing is awesome. For a big system, the desire to just "do a huge water change" gets expensive.

 

[C. Eymann]

Well, I mean think about it, even a small 20-25 gallon daily w/c is going to run you around $5-6+ in salt and RO/DI filter replacement.

In as little as 4-6 months you would have easily enough $$$ for a really nice Calcium reactor setup, that will then literally cost pennies a day to run from then on.

 

[dantimdad]

Already responded guys. Thanks anyway.

This thread can be closed.

 

[pdxmonkeyboy]

Hey man, i dont think it was meant to be a pile on. We were typing while the updates were posting.

Belive me, i would LOVE if i could just have a dual peristalic pump with fresh water keeeping everything in check.

Anywho, at least you are putting your ideas out there and that is what this place is about.
Cheers

 

[dantimdad]

Hey man, i dont think it was meant to be a pile on. We were typing while the updates were posting.

Belive me, i would LOVE if i could just have a dual peristalic pump with fresh water keeeping everything in check.

Anywho, at least you are putting your ideas out there and that is what this place is about.
Cheers

Thanks bud. I really do appreciate the input.

I didn't expect someone to post the exact article I needed that quickly.

 

[Randy Holmes-Farley]

Water changes are very inefficient and VERY costly for maintaining alk and calcium, relative to other methods.

 

[Randy Holmes-Farley]

Already responded guys. Thanks anyway.

This thread can be closed.

FYI, threads are never closed since others may want to follow up in various ways.

 

[User]

I’d like to follow up!

‘Waves hand in air’


Any reason to run a carx AND do 2-3% daily autowater changes? Or does that screw with the carx?

I’m planning to get an AWC soon (2-3 months) but have been doing some math and was thinking of getting a calcium reactor sooner (<6 months) rather than later and dosing 2 part until then.

I feel like paying for an AWC then adding a CaRX within 2-3 months is just throwing money away.

Thoughts?

 

[Magellan]

As long as the water being changed out has the correct dkh, salinity, and Ph it would definitely benefit your reef imo. There are dozens of trace elements found in seawater that our corals need, (not just calcium and alk) and water changes help keep those levels up. Never mind the additional nutrient export that would provide! Is that the most cost effective way of keeping a stable reef? Perhaps not, but then again if cost was the main concern none of us would be in this hobby to begin with!

would it screw with the CaRX? All things being equal, if the levels of calcium/dkh in the water being replaced are the same as the new water, I don’t think so.

 

[User]

As long as the water being changed out has the correct dkh, salinity, and Ph it would definitely benefit your reef imo. There are dozens of trace elements found in seawater that our corals need, (not just calcium and alk) and water changes help keep those levels up. Never mind the additional nutrient export that would provide! Is that the most cost effective way of keeping a stable reef? Perhaps not, but then again if cost was the main concern none of us would be in this hobby to begin with!

My understanding was that adding dissolved coral bones to the tank via the card would add back EVERYTHING a growing coral needs. Bunch of posts basically saying that. You feel like that’s untrue, or incomplete, in your opinion?

Nutrient export is a good point- but I’m having to dose nitrate and phosphate (currently) so if I want to drop them down, I just don’t add it that week.

 

[Magellan]

My understanding was that adding dissolved coral bones to the tank via the card would add back EVERYTHING a growing coral needs. Bunch of posts basically saying that. You feel like that’s untrue, or incomplete, in your opinion?

Nutrient export is a good point- but I’m having to dose nitrate and phosphate (currently) so if I want to drop them down, I just don’t add it that week.

Great point! I’ve been researching the Triton method and it’s made me even more of a believer in regular water changes, but obviously it’s possible to have success with no water changes at all. However, in regards to this specific situation, it seems that the daily 2-3% AWC would help keep your tank VERY stable.

 

[User]

Great point! I’ve been researching the Triton method and it’s made me even more of a believer in regular water changes, but obviously it’s possible to have success with no water changes at all. However, in regards to this specific situation, it seems that the daily 2-3% AWC would help keep your tank VERY stable.

So, can you tell my wife I need a carx and an AWC for Christmas, lol

 

[Magellan]

If you will tell my fiancé I need a bigger tank for Christmas, consider it done !!

this link is to one of my favorite tanks on YouTube, listen to what this lady says about her constant water changes (she is adding trace elements to her top off water as well). I think her success speaks for itself!