Water Chemistry: Scientific Method vs. Rumours and Hearsay

[darrowj]

Water Chemistry: Scientific Method vs. Rumors and Hearsay

One of the most frustrating things about this hobby is how much I do not still know after spending thousands of dollars and a couple of years taking part in it. Is there a resource where I can read and clearly understand the cause and effects of varying aspects of water chemistry? I’m thinking of something written for a non marine biologist.

I ask after having a long conversation with a person at a LFS. It started with me picking up a bottle of liquid calcium because I tested and found calcium was low in my tank. I was also looking for some phosphate pads. Nutshell version is that I did not buy the product or anything else from the store.

Below are some points I remember from the conversation (paraphrasing):

1. "Don't add liquid calcium as it will inversly your magnesium levels. Think of calcium and magnesium as being on opposite ends of a seesaw."

2. "Don't buy phosphate pad or other related products. They remove phosphates too slowly and are not worth the money. The pads will only work well with low PH level like 7.0 and that is too low for a marine tank to handle."

3. "Testing PH is a *almost* a waste of time without knowing your alkalinity. The reason being is that your PH can swing wildly over the course of the day."

4. "If your calcified algae starts to shrink you are in big trouble and you need to react right away as your tank is going to crash soon."

5. "The best way to remove nitrates, remove phosphates, add calcium, add magnesium and get your alk/PH to proper levels is routine water changes. Adding or removing individual things impacts other things and can make your water chemistry much worse."

Some of the above I knew and others did not. Some might be right and others wrong. The point is that the person explained things in common language that were easy to understand. I really wish there was a single resource I could read to explain these things using concrete numbers for levels and easily understood relationships.

To date I have not found such a resource. Books seem to have bits and pieces. Some people I talk to are very experienced but others aren't and rely on rumors and hearsay. Everyone gives advise though and we need to use trial and error to determine who is right and wrong. It can get expensive in an already expensive hobby.

 

[naturebatslast]

Below are some points I remember from the conversation (paraphrasing):

1. "Don't add liquid calcium as it will inversly your magnesium levels. Think of calcium and magnesium as being on opposite ends of a seesaw."

2. "Don't buy phosphate pad or other related products. They remove phosphates too slowly and are not worth the money. The pads will only work well with low PH level like 7.0 and that is too low for a marine tank to handle."

3. "Testing PH is a *almost* a waste of time without knowing your alkalinity. The reason being is that your PH can swing wildly over the course of the day."

4. "If your calcified algae starts to shrink you are in big trouble and you need to react right away as your tank is going to crash soon."

5. "The best way to remove nitrates, remove phosphates, add calcium, add magnesium and get your alk/PH to proper levels is routine water changes. Adding or removing individual things impacts other things and can make your water chemistry much worse."

1. Not a seesaw, but lower Ca levels can drive Mg levels down. Ca and Alk can seesaw, but that's why we want to dose Ca and alk in a manner that's balanced.

2. That's Hooey! Some phospates removers are junk, but ganulated ferric oxide, when used correctly can effectively reduce phosphate levels.

3. Mostly correct.

4. Calcified algae starting to shrink is not a good thing, but it's far from a tank crash.

5. The best way to remove nitrates and phosphates is regular WC's. Maintaining pH, alk, Ca and Mg theoretically should be at proper levels when the salt is mixed, but is often not the case. Alk, Ca and Mg are used by the tanks inhabitatants and regular dosing help maintain proper levels, especially in reef tanks.

I would read articles by Randy Holmes Farley, don't worry about the equations, just go for the messages. He has a bunch of articles in Advanced Aquarists here, just use "water chemistry" in the search field...
http://www.advancedaquarist.com/search.htm

 

[alpha0r]

1, 2 make no sence to me. 3 I somewhat agree with and 5 I agree but with some important reservations.

If your mag is low, adding CA or ALK can effect the other. For example with low mag boosting your CA can lower your ALK or at least make it hard to raise.

I think many reefers on the board would disagree with 2 though personal experience.

Concerning 5, yes WC will remove bad things but many salt mixes are too low on CA ALK and Mag to boost your levels. For example my IO mixes to 360, 11.5, and 1160 respectively. The CA and Mag are much too low and I must boost the levels in the WC water before the WC.

 

[~Flighty~]

Randy Holmes-Farley is your man
http://www.reefcentral.com/forums/showthread.php?s=&threadid=207351
and a hyperlinked list of articles
http://archive.reefcentral.com/forums/showthread.php?s=&threadid=102605

 

[Greg Hiller]

Don't forget, Randy will be talking to the club in Dec. It will be a question and answer session only, so come with your questions.

>1. "Don't add liquid calcium as it will inversly your magnesium levels. Think of calcium and magnesium as being on opposite ends of a seesaw."<

You can independently boost calcium without effecting magnesium levels. If you have low calcium then add liquid calcium (calcium chloride). However once you have both calcium and alkalinity where they should be, then use a balanced additive, one that adds both calcium and alkalinity.

>2. "Don't buy phosphate pad or other related products. They remove phosphates too slowly and are not worth the money. The pads will only work well with low PH level like 7.0 and that is too low for a marine tank to handle."<

They might not be worth the money considering how much they remove. I think you are better off with GFO in a Phosban type reactor.

>3. "Testing PH is a *almost* a waste of time without knowing your alkalinity. The reason being is that your PH can swing wildly over the course of the day."<

Testing pH can be useful, but IME/IMO even if the pH in your tank is a bit on the low side as long as you have alkalinity a bit on the high side you are okay. Testing pH without a probe however is kind of pointless as most of the test kits for it are not good enough to distinguish the levels you will be looking at. You want to know whether your tank is at 7.7 or 8.4. Most test strips and pH kits are not going to tell you this.

>4. "If your calcified algae starts to shrink you are in big trouble and you need to react right away as your tank is going to crash soon."<

Tanks don't necessarily crash because coralline algae stops growing, but it can be a sign of low calcium, alkalinity or magnesium. You should be testing for all three, and be dosing to keep them up if you have corals that are consuming them quickly.

>5. "The best way to remove nitrates, remove phosphates, add calcium, add magnesium and get your alk/PH to proper levels is routine water changes. Adding or removing individual things impacts other things and can make your water chemistry much worse."<

If you are using water that has all the parameters in balance, certainly water changes will help fix all those problems. However, it can be costly if you have corals that are consuming certain components, or if you are feeding fish a lot (adding phosphate). Sometimes it is less expensive to solve the problems individually. It partially depends upon how 'intense' your system is, how much you understand your tank, and how much you understand about the chemistry and how to fix it. If you make a mistake, you certainly can screw things up fast by adding something you don't understand.

Nitrates can be reduced by a functioning sand bed. Phosphate can be removed selectively by granular ferric oxide (GFO). Calcium and alkalinity can be added by a balanced additive. Magnesium can be added as a mix of magnesium chloride and magnesium sulfate.

 

[darrowj]

One stop shopping

Randy Holmes-Farley is your man
http://www.reefcentral.com/forums/showthread.php?s=&threadid=207351
and a hyperlinked list of articles
http://archive.reefcentral.com/forums/showthread.php?s=&threadid=102605

Wow thanks. I have not run across this index before http://archive.reefcentral.com/forums/showthread.php?s=&threadid=102605 thank you

 

[phaedraeos]

This is an awesome book - highly recommended:

http://www.amazon.com/Marine-Chemistry-Chris-R-Brightwell/dp/0793805740/ref=pd_bbs_sr_1?ie=UTF8&s=books&qid=1215619187&sr=1-1

 

[darrowj]

This is an awesome book - highly recommended:

http://www.amazon.com/Marine-Chemistry-Chris-R-Brightwell/dp/0793805740/ref=pd_bbs_sr_1?ie=UTF8&s=books&qid=1215619187&sr=1-1

Looks like exactly what I'm looking for in a book. Thanks for the recommendation. I'm going to pick it up as I have *not* seen it in the BRS library.

 

[Chuck Spyropulos]

Book Reference

In addition to the above references, "Natural Reef Aquariums" by John Tullock has a great chapter on water chemistry. The club may have a copy of this book available for members to borrow.

Here's a link to a description on Amazon:

http://www.amazon.com/Natural-Reef-Aquariums-Simplified-Approaches/dp/1890087009

 

[Greg Hiller]

Marine Chemistry
Chris R. Brightwell

Hmmm...written in 2007. I was not aware of this book.

 

[Chuck Spyropulos]

Books

Yes, me too! Also, Tullock has a new book specifically on Water Chemistry as you can see in the link I posted to the "older" Tullock book.

Marine Chemistry
Chris R. Brightwell

Hmmm...written in 2007. I was not aware of this book.

 

[maurod]

Does anyone else here throw cups of CaCl or MgCl directly into their sump?
M

 

[phaedraeos]

I own a copy of Marine Chemistry, so I'll bring it to the meeting if anyone wants to browse through it. The the thing I really enjoy about this book that it actually lists the scientific equations for many of the processes going on in a reef, but I still think it's simple enough for the lay person to follow.

I'll have it at the water testing table for anyone that wants to take a look

 

[stingythingy45]

Does anyone else here throw cups of CaCl or MgCl directly into their sump?
M

I do,but it's a 70 gallon basement sump.
I find myself dosing about 60 ml or 2 shots of both calcium and alk suppliment daily.
I test for these every Saturday and Mg every other weekend.

SG 1.026
Mg 1500
Alk 12 DKH
Calcium 500 ppm.

>>5. "The best way to remove nitrates, remove phosphates, add calcium, add magnesium and get your alk/PH to proper levels is routine water changes. Adding or removing individual things impacts other things and can make your water chemistry much worse.<<

Just one comment on this.It really depends on the size of the tank.Calcium/Alk/Mg suppliments are nessasary IMO for larger tanks.But many of the Nano folks in the hobby just do water changes with a good quality Reef salt mix that has elevated trace elements.

 

[Chuck Spyropulos]

Mg

I just did tonight. I tested the Mg and found it to be a little low at 1100.

Does anyone else here throw cups of CaCl or MgCl directly into their sump?
M

 

[Randy Holmes-Farley]

I've not read his book, but I would not recommend anything Chris Brightwell wrote on seawater chemistry. He hawks several ludicrous products through his company that clearly show a total lack of understanding of chemistry (or, being more cynical, more interest in money that truth). For example, one that puts magnesium into limewater, where it is totally insoluble and may deplete some of the alkalinity.

We discuss his product line here:

http://www.reefcentral.com/forums/showthread.php?s=&threadid=1425890

and

http://www.reefcentral.com/forums/showthread.php?s=&threadid=1347982

When he worked for Kent, I had a long debate with him about Kent Liquid Reactor here, where IMO, he showed his ignorance of seawater chemistry:

http://www.reefcentral.com/forums/showthread.php?s=&postid=3179214#post3179214

 

[Greg Hiller]

I had no idea this is the same guy from 'Brightwell products'....hmmm....

 

[darrowj]

I've not read his book, but I would not recommend anything Chris Brightwell wrote on seawater chemistry. He hawks several ludicrous products through his company that clearly show a total lack of understanding of chemistry (or, being more cynical, more interest in money that truth). For example, one that puts magnesium into limewater, where it is totally insoluble and may deplete some of the alkalinity.

We discuss his product line here:

http://www.reefcentral.com/forums/showthread.php?s=&threadid=1425890

and

http://www.reefcentral.com/forums/showthread.php?s=&threadid=1347982

When he worked for Kent, I had a long debate with him about Kent Liquid Reactor here, where IMO, he showed his ignorance of seawater chemistry:

http://www.reefcentral.com/forums/showthread.php?s=&postid=3179214#post3179214

That is too bad. I have a very basic understanding on water chemistry and I'm simply looking to learn more on the subject. However, I don't want to waste my time on something to steer me in the wrong direction. Based on your description of this author's resume it sounds like a waste of time to read.

 

[Randy Holmes-Farley]

I do not know if there is anything inaccurate in his book, but many reef books are poor in reef chemistry. Since it is cheaper anyway, you might start with my articles in the link. They often go into greater detail and justification than most folks need, but the reason for that is to substantiate what may end up coming across as an opinion if the basis is not given. I've seen too many reef hobbyists think of science as something best decided by poll, so my hope was to reduce that opinion.

 

[alpha0r]

I do not know if there is anything inaccurate in his book, but many reef books are poor in reef chemistry. Since it is cheaper anyway, you might start with my articles in the link. They often go into greater detail and justification than most folks need, but the reason for that is to substantiate what may end up coming across as an opinion if the basis is not given. I've seen too many reef hobbyists think of science as something best decided by poll, so my hope was to reduce that opinion.

I have personally benefited greatly from Randy's articles. He helped me gain the understanding of marine chemistry that I have. Some parts get technical but he writes clearly enough that anyone could follow along and he usually writes the conclusion so that a monkey could understand it. I would definitely start with his articles before buying a book. Thanks Randy!