Oils from feeding salmon to a reef tank

[Miami Reef]

I notice a slick sheen of oil on the water's surface when I insert raw salmon into the tank.

I’ve very recently started feeding salmon because I’ve heard of some reefers doing it, and salmon seems like a super healthy superfood to provide a tank.

Besides the apparent oil and the breakdown of the skimmer production (the bubbles get depressed and pop prematurely) (can someone explain the science of what’s happening to the skimmer when oil gets released?)

Is feeding salmon a poor or good choice for a reef tank, both for the inhabitants and for the actual water quality itself (oils released into the water column)?

Thanks in advance.


@Randy Holmes-Farley

 

[etcee]

Curious what the conesus will be. I have fed halibut, scallops' other white fish to my tank. Not sure about salmon, however, I have wanted to test this.

 

[BrokenReefer]

Do you mind if I ask why you are feeding raw salmon? What are the supposed benefits for fish?

 

[Miami Reef]

Do you mind if I ask why you are feeding raw salmon? What are the supposed benefits for fish?

High in proteins, fats, and omega 3, astaxanthin from the salmon feed which can improve reds in fish, inexpensive etc.

 

[BrokenReefer]

High in proteins, fats, and omega 3, astaxanthin from the salmon feed which can improve reds in fish, inexpensive etc.

Interesting. For whatever reason my brain reasoned that the Omega 3 benefit was human only (despite it being in a lot of dog foods, I know I know)… thanks for the reply!

 

[Reefering1]

Are you feeding sockeye or farm raised? I typically eat sockeye. I just ate salmon, it seemed excessively oily and kind of mushy. Dug the package out the trash and saw that I accidentally grabbed the farm raised version.

 

[Miami Reef]

Are you feeding sockeye or farm raised? I typically eat sockeye. I just ate salmon, it seemed excessively oily and kind of mushy. Dug the package out the trash and saw that I accidentally grabbed the farm raised version.

I’m feeding farm raised. I can switch to sockeye if that’s a better alternative. I just want the best for my tank.

 

[ReeferHD]

sockeye/wild caught would definitely be a better option for the fish and for yourself too IMO

 

[Reefering1]

I’m feeding farm raised. I can switch to sockeye if that’s a better alternative. I just want the best for my tank.

I don't have any science to back up my opinion. But It definitely seems cleaner than farm raised. I even noticed that the lines between flakes(fat) was thicker as I was cooking it, the skin seemed thicker and burned more but still had a slimy feel on the meat side.. I imagine farm raised eat a different diet and possibly get antibiotics or other medicine/ treatments.

 

[CoralB]

I notice a slick sheen of oil on the water's surface when I insert raw salmon into the tank.

I’ve very recently started feeding salmon because I’ve heard of some reefers doing it, and salmon seems like a super healthy superfood to provide a tank.

Besides the apparent oil and the breakdown of the skimmer production (the bubbles get depressed and pop prematurely) (can someone explain the science of what’s happening to the skimmer when oil gets released?)

Is feeding salmon a poor or good choice for a reef tank, both for the inhabitants and for the actual water quality itself (oils released into the water column)?

Thanks in advance.


@Randy Holmes-Farley

I think it should be a fine choice my only concern would be the oil film you mention and if it’s covering the surface and it’s messing with your skimmer how are you getting proper gas exchange as we get from surface agitation and skimming . For that reason and that reason alone I might hold off till you investigate the overall affect of the oil on your system . Please post what you find or experience going forward . Very interested .

 

[Miami Reef]

I think it should be a fine choice my only concern would be the oil film you mention and if it’s covering the surface and it’s messing with your skimmer how are you getting proper gas exchange as we get from surface agitation and skimming . For that reason and that reason alone I might hold off till you investigate the overall affect of the oil on your system . Please post what you find or experience going forward . Very interested .

The skimmer resumed normal operation after about 30 minutes.

I will wait for Randy.

 

[CoralB]

The skimmer resumed normal operation after about 30 minutes.

I will wait for Randy.

What type of skimate material is your skimmer pulling out ? Normal stuff or normal stuff with a lot of oil ?? I guess what I’m asking is if the skimmer which is now working again is pulling out the oil.

 

[Lbrdsoxfan]

sockeye/wild caught would definitely be a better option for the fish and for yourself too IMO

This. I avoid farm raised like the plague, usually it's also 'modified'.

 

[Miami Reef]

For the people saying farmed-raised salmon is inferior, can you please explain why? I know there’s a lot of fear mongering regarding salmon wild/farmed. I just want to understand your reasoning as to why wild caught is better.

I am not pro or against wild/farmed. I would just like to hear your reasoning as to why you believe so.

 

[Lbrdsoxfan]

Usually farm salmon is genetically modified for quick growth for quick sale. It's FDA approved for consumption, just my personal taste to avoid it. IME you can tell the difference from the look & taste or farm raised v. river/lake caught. I doubt the fish would care but I know my fish eat better than I do, lol. I do make the same attempt to lean towards grass fed cows, organic chicken and free range pigs.

 

[C_AWOL]

By just a color enhancing standpoint, sockeye has a higher ppm of astaxanthin content which is nice for the fish in general (worth the extra dollar or so per lb imo).
I haven't noticed any long term issues from using it in some of my diy fish food blend other than the fact that some fish seem to dislike the flavor (notably my female porcupine puffer and oldest emperor angelfish wont touch the stuff at all with it in the mix)

 

[Randy Holmes-Farley]

Besides the apparent oil and the breakdown of the skimmer production (the bubbles get depressed and pop prematurely) (can someone explain the science of what’s happening to the skimmer when oil gets released?)

What is Skimming? by Randy Holmes-Farley - Reefkeeping.com
Bubble Popping
Other critical things can occur at the foam draining stage, and they usually impact skimming negatively. One is the addition of materials that cause bubbles to pop prematurely. Excessive oils, for example, cause this to happen.

When typical oil droplets are added to a reef aquarium, they quickly arrive at the skimmer. A pure oil droplet is largely hydrophobic on all sides. Oil drops work their devilish tricks in skimmers by spanning across the water between two air bubbles in a foam (Figure 4). Once an oil droplet spans the water gap between bubbles, the amphipathic molecules on both of the bubbles' surfaces spread along the interface between the oil and the water (if they were not there already) and connect both of the air gaps with a continuous line of amphipathic molecules along this oil/water interface. Once these amphipathic molecules are in place, the interaction is unstable. The surface tension pulls at the oil drop (Figure 5), and it simply comes apart. The bubble ruptures from the site of the oil drop, and the effect is that the bubbles combine, or pop entirely. The reason that this does not happen in the absence of an oil drop is that to cause a rupture requires the water present between the air bubbles (or between a single bubble and the nearby atmosphere) to become exposed as fresh air/water interface. In fact, it requires a continuous line of water molecules to become exposed all at once.

Because such a rupture would require a large number of hydrogen bonds to be broken simultaneously, it simply requires too much energy to actually take place. When the oil drop is there, the water molecules are no longer exposed, but rather the oil or amphipathic molecules, which are much "happier" to be exposed to air, and the droplet ruptures, breaking the bubbles on either side of it into one larger bubble. That process continues until no foam remains.

Bubble popping can also be caused by hydrophobic solids, although that process is likely less important to aquarists than is popping due to oils.

Bubble Popping in Marine Aquaria
The effects of this bubble popping process, if not the mechanistic details, are easily observed in an aquarium, where many things may cause a bubble popping effect. One cause that most aquarists encounter is oil from their hands. After reaching into a saltwater aquarium, skimming action often comes nearly to a halt as bubble popping dominates foam drainage and collection. The popping will proceed until the oil is somehow removed. Among other ways, oil can be removed by splattering it above the foam height in the skimmer, being foamed out bit by bit, being emulsified into the general foam as very, very tiny droplets which no longer span air bubbles, becoming attached to solid objects and removed, being consumed by tank microorganisms and by eventually dissolving into the bulk tank water. Many foods used by aquarists have a similar effect on skimmer bubbles.

As an aside, the bubble popping action of hydrophobic oils is exactly how most anti-gas medications for humans function. Simethicone is really polydimethylsiloxane, which is a hydrophobic polymer liquid. It pops bubbles in your stomach or intestine, and permits the gas to be eliminated. Antifoaming agents also are the basis for a large number of industrial products that work on the same principle. Other things also cause bubble popping. One of these is the fatty acid supplement Selcon. It causes bubble popping in the same fashion as skin oil droplets. Hydrophobic solid objects can also cause popping. Fine particles of activated carbon, sand, inorganic precipitates, or granular ferric oxide/hydroxide, once coated by organic compounds, can serve to break foams in a manner analogous to the described for liquid oils.

 

[Randy Holmes-Farley]

Usually farm salmon is genetically modified for quick growth for quick sale. It's FDA approved for consumption, just my personal taste to avoid it. IME you can tell the difference from the look & taste or farm raised v. river/lake caught. I doubt the fish would care but I know my fish eat better than I do, lol. I do make the same attempt to lean towards grass fed cows, organic chicken and free range pigs.

Usually?

Last I heard, only one company farmed genetically modified salmon. Many stores do not sell it at all, including whole foods, Safeway, and Kroger.

 

[liudachris]

For the people saying farmed-raised salmon is inferior, can you please explain why? I know there’s a lot of fear mongering regarding salmon wild/farmed. I just want to understand your reasoning as to why wild caught is better.

I am not pro or against wild/farmed. I would just like to hear your reasoning as to why you believe so.

I’ll just throw in my 2 cents here as someone who prepares and eats a lot of raw fish at home. The one big risk you take with eating raw wild caught is parasites. The exception is if the fish has been flash frozen below zero for several hours or cooked through. Personally if I’m feeding raw I’d go with farm raised from a reputable source. The diet is parasite free. Im not sure if salmon parasites can get into ornamental aquarium fish.

 

[Lbrdsoxfan]

Usually?

Last I heard, only one company farmed genetically modified salmon. Many stores do not sell it at all, including whole foods, Safeway, and Kroger.

I understood the opposite (may very well be wrong), there was more than a few farms raising modified salmon.

Either way, farm raised (or GMO) is a hard pass for me.