Effects of feeding too much on tank water quality

[islandguy11]

Regarding water content, just a couple of examples. For most fish foods, the guaranteed analysis between the frozen version, and the freeze dried version, of a single unit (in the first example a single mysis) will be identical, the only real difference is that one will have 98% of its moisture removed.

When you dehydrate or freeze dry a food, it will shrink in size, but the protein/fat content remains the same. The only thing that changes is the amount of moisture, so one needs to be careful so as not to overfeed a freeze dried product (because it appears much smaller) than the same food in its original or frozen state.

So ounce for ounce a fish will glean far more protein out of a dry food, than they would the same amount (per ounce) of a frozen product, due the majority of the weight from a frozen food being from the high moisture content. The same applies to most pellets as most dry food products have approx. 10% moisture content (or less).

Water is a non nutrient, so while it may help increase palatability, and possibly aid in digestion, it will also make a fish reach satiation much quicker then if fed dry food. It's like drinking a couple of glasses of water, before you sit down for your platter of surf & turf. You won't be nearly as hungry. Probably a good thing for those that overfeed by large amounts, but not such a good thing for those that tend to under feed.

The following Nutritional analysis provided by Piscine Energetics (PE Mysis)

Frozen Mysis

Protein 10.46
Crude Fat 3.29
Moisture 82.27
Ash 1.65
Carbohydrates (by subtraction) 2.3


Guaranteed Analysis from dry weight (freeze dried)

Min Crude Protein 69.5%
Min Crude Fat 8.35%
Max Crude Fiber 2.75%
Max Ash 5.5%




Another example.

A typical analysis of freeze dried bloodworms.

Guaranteed Analysis
Min. Crude Protein...55%
Min. Crude Fat.....3%
Max. Crude Fiber.....5%
Max. Moisture..... 5%



A typical analysis of frozen bloodworms. (from the same manufacturer as above)

Guaranteed Analysis
Min. Crude Protein..........6.3%
Min. Crude Fat............... 0.8%
Max. Crude Fiber........... 0.3%
Max. Moisture.......91.2%



Approximate analysis of earthworms was completed by Dr. Carl Cater in the Oilseed Products Laboratory at Texas A&M. He reported that on the samples tested moisture (volatile) averaged 80.44%. A further analysis of freeze-dried earthworms indicated the following components: oil 6.8-7.1%, nitrogen 10.6 - 11.0%, protein 66.2 - 68.6% and ash 9.3 - 9.7%. This would indicate that on whole, live earthworms are less than 14% protein. Therefore its use as food or a feed supplement would probably be limited.


This is something that I attempted to explain when Repashy first hit the market several years ago. Some people got it, and some I reckon aren't so good at math.

Repashy Superfood (for cichlids)?

I came across this product on Ted Judy's YouTube channel. I've always found his videos extremely informative and he is an excellent hobbyist but i can't say I've ever seen him endorse a product like this before. Repashy is a gelatin based food which comes in powder form. As you will see in Ted's...

www.monsterfishkeepers.com

To which the owner, Allen Repashy, never did answer the following question;

Can you please provide the members here with a nutritional analysis based on the finished product designed for carnivores, as in once the dry powder has been reconstituted with tap water? Thanks.

……. because if he had, it would have shown his finished formula, that was 75% water (give or take), containing but a small fraction of the nutrient levels shown on his packages, which he had listed on a dry matter basis.

Thanks for sharing that Neil -- btw, congratulations at hitting 10,000+ posts, that's a lot of info and help passed on to others (and a few heated debates along the way lol, but none can deny your contribution).

 

[RD.]

You're welcome, and thanks. Only fitting that I hit the 10K mark in a food/feeding discussion. lol

 

[Coryloach]

I am wondering what do you guys think on malnutrition?

Some quotes on the matter:

Unfortunately underfeeding seems to have become a means of managing water quality in tanks which are too small for the species being kept. Many keepers don’t realise that this is what they are doing. They take advice not to overfeed and follow this advice carefully. However, due to inexperience they don’t appreciate the bigger picture and often don’t realise their fish are suffering from malnutrition. Goldfish, for example, eat a huge amount of food and are naturally very large fish. It would not be possible to keep a goldfish in a small tank and feed it the right amount without experiencing poor water quality.

An underfed fish will not have enough nutrients for it to grow properly. Its bones, muscles and internal organs will not develop properly. It will be small and ‘weedy’ compared to healthy examples of its species. It is unlikely to achieve its full life span.

Feeding your fish a lot of the wrong food can also have an impact on whether or not they grow and develop properly. A carnivorous fish given food suitable for vegetarian fish will not get the right sort of nutrients for their needs and vice versa. Species have evolved to eat the types of food available in their natural locations and this is what their keepers should try to replicate, as far as is possible and legal, in the home aquarium.

Norton Aquatics (online) state the following as the effects of malnutrition on fish which clearly a shows a link between malnutrition and poor growth:

Effects of Malnutrition on Fish.
The effects of malnutrition are listed by the mineral/vitamin and what condition is caused when the substance is lacking in the diet.

• Vitamin A – Eye problems, loss of appetite, impaired growth, intramuscle and fin-base haemorrhage (internal bleeding), anaemia, dropsy, weakened gills.
• Vitamin B (complex) – Loss of appetite, poor growth, fragile blood vessels, poor growth, anaemia, muscular wasting, convulsions, loss of equilibrium, cloudy eyes, poor vision, over-pigmentation, gasping and flaring of gill covers.
• Vitamin C – Loss of appetite, over-pigmentation, eye haemorrhage, deformed cartilage and spine (commonly seen as a zig-zag shape from the dorsal to tail-fin – a ‘kink’ in the tail), intramuscular haemorrhage, anaemia, fragile blood vessels.
• Vitamin D – Poor growth.
• Vitamin E – Muscular wasting and poor growth.
• Biotin – Loss of appetite, poor growth, muscular wasting, convulsions, intestinal lesions and convulsions.
• Choline – Poor growth, poor food conversion, fat collection in liver, kidney and liver haemorrhage.
• Folic Acid – Poor growth, lethargy, fragile fins, over-pigmentation and anaemia.
• Inositol – Poor growth, distended stomach (dropsy – collection of fluid in the body cavity), skin lesions and increased stomach emptying time.
• Niacin – Loss of appetite, rectal lesion, muscle spasm, skin haemorrhage, skin lesion and anaemia.

Thiaminase
Some species produce an enzyme called thiaminase. This is a digestive enzyme which destroys thiamine (vitamin B1). Predator fish feeding on species which produce thiaminase can suffer from thiamin deficiency which can cause a variety of symptoms including poor growth (Lichtenberger, 2011).

Cortisol
Cortisol is a stress hormone that has been shown to cause reduced growth in various species of fish including goldfish by suppressing the appetite and reducing their ability to convert the food to energy (comparativephys.ca). Stress can come from overcrowding, poor water conditions, malnourishment, aggression from other tank mates, inappropriate décor such as lack of hiding places, to name but a few.

Muscle atrophy and lack of fitness
Fish housed in too small tanks will not be able to swim about as they should. This means that their muscles will not develop properly so the fish will not have the muscle tone and bulk that it would if it were fully fit.


Source:
http://injaf.org/the-think-tank/do-fish-grow-to-the-size-of-their-tank/

 

[skjl47]

I am wondering what do you guys think on malnutrition?

Hello; I know another fellow who argues the way you do. That being going to the extreme example to try to make points. Being the OP of this particular thread let me clarify that the point was about TOO much food actually eaten by a fish and what effects that may have.

A logical reaction to overfeeding is to reduce feeding. Not reduced feeding to a point of malnutrition as your post seems to imply. Light feeding and skipped days with no feeding does not necessarily equate to malnutrition. There can be a happy middle path.

 

[jaws7777]

I think its allot easier to over feed than under feed and most likely more common.

 

[skjl47]

I think its allot easier to over feed than under feed and most likely more common.

Hello; Not that I have seen a huge number of tanks just because I have kept fish a long time, but of the fairly decent number I have seen or known of the single biggest mistake people make is to overfeed.

 

[Coryloach]

Being the OP of this particular thread let me clarify that the point was about TOO much food actually eaten by a fish and what effects that may have.

Apologies, I didn't realize you've imposed restrictions....

A logical reaction to overfeeding is to reduce feeding. Not reduced feeding to a point of malnutrition as your post seems to imply.

I've only posted one sentence. The rest of it is quoted from the link in relation to reduced feeding in the fear of overfeeding. I thought it's relevant.

 

[jaws7777]

Hello; Not that I have seen a huge number of tanks just because I have kept fish a long time, but of the fairly decent number I have seen or known of the single biggest mistake people make is to overfeed.

Yup agreed. Im guilty of it myself. I had 1 fish hold out for almost 2 months because i didnt feed her what she wanted. That tells me allot about how often they NEED to eat.

 

[Coryloach]

I once tested the capacity of a baby clown loach in quaratnine to see what he'd eat all at once. He was a hungry bugger when small... I dropped a full cube of frozen bloodworms. He gobbled majority of it in minutes then he stopped short of finishing it and left the rest to the cherry shrimp. He was "meditating" for a few minutes afterwards and then he went doing his normal rounds with a slightly rounded belly. The tank was a 15 gallon. Now if I had 5 baby clown loaches and I dropped 5 cubes of frozen bloodworms in this tank, I would have been overfeeding.....not the fish but the tank...

 

[dan518]

I personally think as many people under feed as over feed, I was going to post the same article that C Coryloach did. If people are that worried about water quality then cut the stock down.
Seems to be alot people that have a one size fits all approach to feeding. Different fish require different feeding requirements. For example oscars have a small defined, delicate sacular stomach, large items can damage it and it doesn't have the ability to process huge amounts of food in one go. Hoplias have huge cone shaped stomach capable of digesting huge prey items. Feeding the same regime to these fish would be far from ideal.