The Puffer Forum

RTR wrote:Hobbyists have a lot of confusion about pH. For fish like F-8, a pH test is at best a hint with little useful data. Hobbyist tend to think that water pH conveys a lot more information than it does in reality. Changes in pH may be highly significant - comparing the pH over a period of time can show you that alkalinity is being lost, used up, which is full normal and natural. But LFS staff and too many hobbyists think yhat boosting the pH is correcting a water problem. This is how folks get in trouble with commercial buffers (mostly phosphate-based). Yes, those solution can amd will temporally raise the pH, but unfortunately they do nothing at all for the carbonate/bicarbonate hardness (i.e., alkalinity), which is very important for fish like the F-8. When carbonate/bicarbonate hardness is used up, it absolutely cannot be replaced with phosphate hardness. Both are important for these fish's metabolism, but neither one can do the other ones job. Trying to judge water change needs by pH is fooling yourself. Phosphates and carbonates must be measured independently. They do very different jobs in the fish's metabolism.

For low brackish water fish such as F-8, you really need a soluble substrate such as aragonite to add carbonate/bicarbonate as needed. If you feed a variety of foods, or locally reared snails and shrimp which have been fed a variety of foods, their phosphate requirements will be met. Remember, you are what your prey eats.

If this is not clear, let me know - it is very, very important. HTH

I've just drank two cans of monster so it looks like I'm not sleeping until the early hours x]. I'll make use of tonight by obsessively learning what I can about these. I love a little project and a challenge

I was trained into biomedical research back in the dark ages. My second SW tank was an invert tank with an algal bed filter (equal in size to the invert display tank). That was back in the late 1960s - the dark ages compared to current knowledge and practices. Back then you learned fast or your critters died. At least I had the background so cultures were not mysterious to me. Biochemistry and physiology were not foreign languages as they were to most hobbyists, and still are to many folks.

Parameter readings such as pH are useful, but misunderstood by many folks, unfortunately including too many LFS employees and owners. Yes, you can increase pH by adding such things as phosphate buffers, but it is not the phosphate that are lacking in established light BW tanks. The missing required material is generally alkalinity, the carbonate/bicarbonate hardness. The pH test does not see the difference between carbonates/bicarbonates and phosphates. The fish's physiology really, really does. Metabolism cannot substitute phosphate for carbonate - it is not at all the same thing. A pH test reads either and both. Low end brackish needs more alkalinity than diluted marine salt mixes provide at low brackish levels. So we need to have a reservoir of soluble carbonate/bicarbonate always available. Aragonite substrates provide that material. Periodically (years) we have to add more aragonite to replace what has been used up after dissolving to preserve the water's KH. It is better here to test KH than pH, or do both tests.

HTH

To check we're on the same page...
So the carbonate carries the calcium in the process of excreting excess calcium?
In aquariums, the carbonate must then be lost through water changes?

Nope, sorry, wrong side of the equation. This deals with other side of the picture, the anions, the negatively charged ions in the solution. Calcium is a cation, positively charged, they are cations. Forget calcium on this matter. We are interested in the opposite polarity, the negatively charged carbonates and bicarbonates versus the phosphates, bi-phosphates,and other phosphate forms also negatively charged. In water solutions, all these ions exist as dissolved ions only, not as compounds as they are when dry.

Calcium is a required material also, but not on concern in this matter, ditto for the phosphate.

This strictly about alkalinity, which in fish keeping refers only to carbonate/bicarbonate hardness. Potassium (K), sodium (Na). calcium (Ca), magnesium (Mg), chlorine (Cl), carbon (C), phosphorus (P), oxygen (O), hydrogen (H) and a number of of other elements are all absolutely required for life on this planet. In biochemistry, these elements combine in multiple different ways. In biology/biochemistry, it is quite common for particular materials to be absolutely required in certain combinations and ways. Carbonates/bicarbonates may well affect the pH of a solution in similar ways to the effects of phosphates or biphosphates - as in pushing the pH of the solution upward to a higher pH. But - a very big but - the carbonate/bicarbonates only very rarely if ever can be replaced in physiology by phosphates, or the opposite. Their pH can be matched, but their biochemistry is not at all replaceable by the alternate compound. In a nushell, this is why "buffers" are rarely of any use in fish keeping, but are constantly being sold by the uninformed to the unaware. If the fish or inert need/requires carbonate/bicarbonate and you offer phosphate instead, it serves no purpose except to modify the water to no valid end.

In other words, commercial "buffers" or other phosphate-bearing materials for low BW F-8s are a waste of money and time and are in effect, pollution. Only carbonates/bicarbonates are required, and aragonite will provide it as needed when it is used as the substrate. It is in this use, the simpest long-tern technique to do this.

Does that help clarify, or make it worse? Let me know and I'll try again...

Oops! I caught one omission: Clarifying "carbonate/bicarbonate". In solution in tanks of water they are essentially the same thing, but the form varies with the pH. At lower pH, the bicarbonate form (HCO3) predominates. The cabonate form (without the hydrogen atom attached) predominates. at higher pH. That sort of variation is characteristic of material which serve as "buffers", i.e., which slowdown pH shifts.

RTR wrote:Oops! I caught one omission: Clarifying "carbonate/bicarbonate". In solution in tanks of water they are essentially the same thing, but the form varies with the pH. At lower pH, the bicarbonate form (HCO3) predominates. The cabonate form (without the hydrogen atom attached) predominates. at higher pH. That sort of variation is characteristic of material which serve as "buffers", i.e., which slowdown pH shifts.

I'm quite confused but I'm sure I'll catch up with more reading.

I could really use some help with a couple of questions, though. - Fish need calcium carbonate as a substrate but several (seemingly reliable) articles propose that boney fish produce and excrete calcium carbonate. Can you explain this to me? i.e. what's the difference is between the calcium carbonate they need and the calcium carbonate they excrete? Also, why can't they derive carbon from the organisms they consume?

Thanks very much for your help, RTR!

Lots of great RTR articles in our Library for you to ponder over!

RTR's article at Badman's is what I always recommend to other F8 hobbiest on other forums. It is a bit of a read but I think it's very concise. I also link TPF's Pufferpedia as well.

http://badmanstropicalfish.com/articles/article84.html

Yeah i like that article
Thanks PP I'll have a browse

Calcium carbonate - in its myriad forms - is common in the earth's crust add rocks - plus in fresh waters as well as in the oceans in much higher levels than in most FW It is also common in fish foods. It is structurally common in modern (boney) fish. The carbonate metabolism is constant in boney fish and animals. Cartilaginous fish - such as sharks and rays have quite different metabolisms. Puffers are/were originally purely SW fish, some members of the family have adapted to BW as well as to pure FW. They still carry much of their SW heritage in their metabolism, with impacts on both calcium and carbonate/bicarbonate metabolisms (which are related but separate). Undissolved calcium carbonate is not secreted or adsorbed (common to many minerals) as an undissolved mineral, but as separate and distinct ions (also common to many minerals from which both the cations and anions are needed or required). Their are specific blood levels needed or required for each separate ion. Those level are amother factor in the metabolic support the blood supplies to the entire body and the many, many separate and distinct ions that each creature needs and highly specialized and specific bio-processes that keep the balances of all those ions individually and distinctly at the optimum levels. The whole dynamic is termed "homeostasis", a six-bit term for the ideal condition of all body components and structures and functions. Many to most fish are either FW or SW. Those two quite different conditions require - no surprise - different physiologies to maintain that fish's homeostasis. BW fish are in quite a different situation. They must adapt to either or both of FW and SW or to something in-between up to multiple times per day (remember tide changes plus intentional swimming fro one condition to another). That is a huge physiologic chore. Fish tanks are relatively stable environments. We try hard and spend all sorts of money and time trying to keep them stable. Unlike in the wild, in captivity stability is king, The real trump card. But stability in glass or plastic boxes is not an attribute of living systems, they can and must change constantly. In isolation, changes are always negative (entropy is always the enemy). Some ions are used up while their changed forms accumulate and that is never positive. We do water changes to restore a water profile as close as possible to the original. The situation is never static. Living systems cannot be by their nature static. The two concepts are mutually impossible. To support a living system, we must remove wastes as well as replenish used-up materials. Think about it - that double requirement is the basis and essential nature of fish-keepimg. Both functions must be accomplished. We have found that light brackish water is suitable for long life (15-20 years) for F-8 puffers. But in finding that "sweet spot" (really a small range with an apparent optimum at 3-5ppm), but water partials alone will not do it without higher levels of carbonate/bicarbonate hardness than than that specific gravity will provide. We also found that using aragonite (the most soluble of the calcareous substrates) will provide that needed extra carbonate/bicarbonate with periodic replenishment of the aragonite substrate as it dissolves over time. You are not even required to test for the carbonate/bicarbonate routinely to check the levels. Such testing periodically may be reassuring, but IME is not essential. I love things that I do not have to monitor. Whatever role calcium carbonates from feces might play in maintaing bioavable carbonates/bicaronates can be ignored. If the water is not carbonate-poor, it may even go away with the residual feces in vacuuming.

Singleton F-8s will also be more active in their old age if they have sight of con-specifics in adjacent tanks. Old tropicals in general tend to be less active in old age (10-30++ years) without such nearby but separately housed fish. They are harder to keep well-nourished without getting chubby in old age. Such sights certainly are more interesting to the hobbyist than an inactive fish. This does not seem to increase or decrease longevity by itself, but I don't have a lot of data there.

HTH

Thanks for the info. I'll carry on researching
Btw, when you say 'We' who are you referring to?

Pretty sure he means, us pufferkeepers.

Yup!

I have rather hard tap water, would that provide sufficient mineral content? I'll get a pH test at some point to be safe.

That depends entirely on you local water supply. England has some areas with great water for fish, and some areas where fish-keepers have nightmare water. (Are Yanks allow to say that we are unlikely to settle in West London, among others?)