Feed fish before stocking?

[HankB]

I have a deeply held belief that one of the most critical aspects of reef keeping is maintaining a balance between waste producers and the biological filter that breaks down the waste. Further, when a tank is new, the balance is tenuous at best.

 

It occurs to me that the bioload related to fish comes ultimately from their food. In the short run they can produce waste by drawing on their fat reserves, but in the long run those are still dependent on food. The issue when stocking fish is that there is a step change in the bioload as the fish are added. If the step is big enough, that can overrun the filter until it has time to catch up.

 

I believe that the food added to the tank - even without fish - will contribute just as much to the bioload as the fish themselves. Either the CUC will eat and process the food or the food will decompose. I reason that by ramping up the feeding over a week or two the biological filter will be conditioned for the arrival of the fish and reduce the chance of wild swings in ammonia, nitrite and nitrates following stocking.

 

I'm curious if anyone else has heard of or tried this. Do you see any potential problems doing this?

 

Our tank package from our dealer (Reef Depot) includes three fish. Reef Depot is suggesting that we add all fish at the same time to reduce the chance of conflict. They'll even put the fish in a tank at their shop by themselves in order to get them acquainted before we pick them up. I see the merit in their suggestion, but I am concerned about the increase in bioload.

 

thanks,

hank

[mpatzer]

I dont think its really the fish themselvs that cause a spike in the ammonia, but rather the food they are being fed and the waste the fish produce because of it. I think if you were to add several fish at once to a nano tank and didnt feed them anythind for a week or longer you wouldnt notice much if any spike in ammonia.

[HankB]

I dont think its really the fish themselvs that cause a spike in the ammonia, but rather the food they are being fed and the waste the fish produce because of it. I think if you were to add several fish at once to a nano tank and didnt feed them anythind for a week or longer you wouldnt notice much if any spike in ammonia.

 

I think we're on the same page as far as the belief that the food is the ultimate source of waste. I see two problems with not feeding. First, the fish will draw on fat reserves and still produce waste. Second, I'm not sure that withholding food will be a good way to acclimate them to their new environs.

 

thanks,

hank

[mpatzer]

True. You are making a good point. Adding one fish usually not a problem but several might. It may not hurt to slowly/slightly increase feeding over time before adding them and then make sure you do an extra few water changes to keep nutrients from building up too much. Good idea on your part.

[geekreef_05]

Agreed that food is the ultimate source of waste.

 

Although I believe that by adding food which goes uneaten you're likely to pollute the tank more than if the fish were actually in there, consuming the food. I would argue that decaying food adds more pollution than fish waste. Thats why overfeeding can be a HUGE problem to some reefers.

 

That said, Im still on board with your idea. My solution would be to simply do a couple larger water changes at the end of the process (30% WC).

 

However I do question the usefulness of it all, due to the given timeline. I expect that building up a significant biological filter would take at least 3 months. And because you already have your fish I wonder how long you'll be waiting to put them in the tank. If your planning on introducing them next week.. then i say you might as well start with them in the tank and mitigate using a couple extra medium-small water changes next week.

 

Just my two cents. Good luck and congrats on your tank/fish.

[HankB]

That said, Im still on board with your idea. My solution would be to simply do a couple larger water changes at the end of the process (30% WC).

 

Thanks, I appreciate your thoughts on this. We don't have the fish yet but plan to in a couple weeks. Or we could hold off.

 

Since it is still a young tank, I am monitoring salinity, nitrates and pH daily. I cover all of the other stuff in the API Reef Master and Saltwater Master kits at least once/week (ammonia, nitrites, phosphates, calcium, KH.) Before and after the addition of anything, I monitor extra closely.

 

I'm also a believer in frequent water changes. I think that's useful to head off problems and even more important when problems crop up. I probably won't do a 30% water change because we're geared up to prepare 5 gallons of water at a time, but I could do multiple 15% water changes should any of our parameters indicate the need.

 

We started stocking (corals and CUC) Friday night and I started feeding yesterday (Sunday morning.) That was target feeding a few brine shrimp to the corals. Later last night nitrates were - if anything - lower than before. I also changed filter floss yesterday and most of the uneaten food probably wound up there.

 

I will continue to monitor closely to see if the biological filter is handling what I throw at it.

 

thanks,

hank

[HankB]

I got some frozen mysis and fed about half the rinsed contents of one cube to several corals and the rest of the tank after lights out last night. That's two feedings now (and one intervening 15% water change.) Nitrates have begun to drop since we stocked with corals and CUC and are now between 10-20 ppm.

 

So far, this experiment looks like a success.

 

thanks,

hank

[HecticDialectics]

I'm pretty sure this is just a reason you should stock -slowly- :shrugs:

 

You're overthinkin' it. Theoretically, you're even contradicting yourself, arguing that food will add "just as much" of a bioload as fish. The solution suggests itself as feed just a liiittle bit, until the filtration capacity builds it, and slowly increase feeding... but stocking slowly results in the same thing... live rock starts off with a certain amount of filtering capacity. Don't overload the tank, and the small bumps won't be bad at all, if even noticeable.

[crrichey]

Just keep in mind that the food going in doesn't equal what is comming out (of the fish that is). Portions of that food become fixated within the fish as protein, cells, etc. Also it takes longer for raw food to break down and go through the nitrogen cycle if it isn't digested by a fish. Even if you were able to portion the right amount of food that would be equivilant to what the overall fish waste produced could be, fish poo will be converted to nitrate faster than raw food. Once your fish are added the biological system will still need to catch up. If you really want to try and balance the tank to a certain bioload level use ammonia. That is basically a fishes #1 export. I have even heard of people peeing in a new system to get the cycle going. A bit gross but would seem to be effective.

[HankB]

I'm pretty sure this is just a reason you should stock -slowly- :shrugs:

 

You're overthinkin' it. Theoretically, you're even contradicting yourself, arguing that food will add "just as much" of a bioload as fish. The solution suggests itself as feed just a liiittle bit, until the filtration capacity builds it, and slowly increase feeding... but stocking slowly results in the same thing... live rock starts off with a certain amount of filtering capacity. Don't overload the tank, and the small bumps won't be bad at all, if even noticeable.

 

Right and maybe.

 

There are also advantages to stocking fish at the same time - to prevent the sort of problems that one encounters introducing fish to a tank that has already been subdivided into territories by previous inhabitants.

 

Just keep in mind that the food going in doesn't equal what is comming out (of the fish that is). Portions of that food become fixated within the fish as protein, cells, etc. ...

 

Good point.

 

We have our initial stocking list:

2 neon gobies

1 firefish goby

1 green chromis

 

So I think that's not too much fish to put in at one time - but maybe stretching things a wee bit. In the mean time I have been feeding mysis and frozen brine shrimp to our corals (and a bit that gets away feeds the bristle worms, cerith snails and hermits.) Probably the only bits that remain uneaten are what gets sucked up by the filter when I turn the pumps back on. Nitrates began dropping from a steady 20 as soon as we introduced CUC and corals and are now at 10 and still dropping in spite of feeding every other day. There are a few spots of diatoms and/or cyano on the bottom that I interpret to be the result of excess nutrients. I'm going to modify my feeding practice to include rinsing the thawed food to eliminate the liquid nutrients that come with them.

 

I took some used floss from the main tank and put it in a box filter in a bare QT tank and that is now reading ammonia so I'm pretty sure that there is uneaten food in the floss that is continuing to break down - as you said more slowly than when the fish eat it.

 

Thanks for sharing your thoughts on this.

 

The experiment continues.

 

-hank

[Ryan_H]

just putting the food in the tank will not be quite the same. the "processed" form a food that the fish produce goes to feed corals and microfauna, while the food itself would just sit and rot with nothing eating it and not achieve the same goal. if you set up your tank properly and choose your fish carefully, they can get a lot of their food from the tank itself as well, and you can't compensate for that, unless you just dump a bunch of dead copepods and algae in the tank every day lol.

[crrichey]

I don't consider anything that is naturally growing in the aquarium as adding to the bioload even if the fish are eating them. It is a net gain, the fish poo feeds the growth of algae and microfauna that feeds copepods. The copepods feed the fish, etc...

[Ryan_H]

I don't consider anything that is naturally growing in the aquarium as adding to the bioload even if the fish are eating them. It is a net gain, the fish poo feeds the growth of algae and microfauna that feeds copepods. The copepods feed the fish, etc...

 

so by your reasoning a mandarin ads 0 bioload to a tank, or if you had a ton of live rock and never fed your fish your nitrates would always be 0.

 

a live copepod is not the same chemical composition as a pooped copepod

[HankB]

Hi folks,

I thought I'd provide at least one more update on this experiment.

 

First I'll comment that my desire was to add something to stimulate bacteria that break down waste. There were some interesting points made regarding that compared to feeding fish. I'm more or less in agreement with those points, but I think they were finer distinctions than what I could apply WRT the quantity of food I was adding.

 

When I started this, our Nitrates were about 20 ppm. During the period, Nitrates steadily dropped in spite of the additional food, most of which was target fed to some corals. Some of the material also made it to the floss in the read chamber which I usually change out every 2-3 days. I know this because I put some in a bare QT tank and detected ammonia and nitrites a couple days later, neither of which we ever detected in our DT. Over the weekend (3 days ago) we added two fish to the tank - a purple firefish goby and a green chromis. Today when I measure Nitrates, it appears to be between 0 and 5 ppm (viewed by sunlight) or 5-10 ppm (viewed by incandescent.) I can't actually tell the difference between the 5 ppm and 10 ppm reference on the API color card.

 

I attribute the drop in Nitrates to continued development of the biological filter as well as uptake by corals and algae. In this latter regard, we are presently experiencing a cyano outbreak. (I believe it is cyano - it also seems to match the description of dinoflagellates, so I am not positive.) this seems likely a result of excess nutrients introduced with the food and keeps the experiment from being a complete success. To deal with this outbreak I am increasing water changes to 2-3 times/week and we will be more careful about overfeeding.

 

Thanks for following along and providing your thoughts on this.

 

-hank

[shiveley]

you're kind of missing the point: the "poo" from "starter fish" isn't what's significant toward initiating biological filtration, it the wide-spectrum of beneficial bacteria present in the "poo" that's important. adding prepared fish foods to your tank will not achieve the same results as the availability and diversity of bacterium present would be minimal compared to what would be introduced to your tank if fish were present.

[krankykris]

i say leave the tank be. you shouldn't have to do anything than add the live rock.

 

http://www.cvreefers.org/showthread.php?t=4270

 

couldn't find the original, but it's a great read.

[HankB]

i say leave the tank be. you shouldn't have to do anything than add the live rock.

 

http://www.cvreefers.org/showthread.php?t=4270

 

couldn't find the original, but it's a great read.

 

I think the original was an email to the poster. Great read - thanks.

[MrAnderson]

did you ever hit zero nitrates in the unstocked tank? you sounded like you started off this "experiement" at 20ppm nitrates, why not wait till you hit zero if your tank was already struggling to catch up in terms of denitrification capacity?

[HankB]

did you ever hit zero nitrates in the unstocked tank? you sounded like you started off this "experiement" at 20ppm nitrates, why not wait till you hit zero if your tank was already struggling to catch up in terms of denitrification capacity?

 

No. We started with LR, LS and water from our dealer's tank. No nitrites or ammonia were ever detectable and nitrates were at 20 from day zero. Two weeks later (with diatom bloom at 1 week and algae starting to take over) we added our CUC and first corals. (Our dealer advocated immediate stocking but we felt better to wait.)

 

Our nitrates started dropping when we added corals and have reached zero about a week ago - about the same time we stocked our first two fish.

 

We didn't wait because it was not clear that nitrates had to be zero before proceeding. Hitchhiker corals and snails looked fine so we proceeded. New introductions have done fine with the exception of a plate (heliofungia) which developed a tear and expired in our QT tank.

 

-hank

[HankB]

i say leave the tank be. you shouldn't have to do anything than add the live rock.

 

http://www.cvreefers.org/showthread.php?t=4270

 

couldn't find the original, but it's a great read.

 

Here's the original: http://www.reefkeeping.com/issues/2004-01/eb/index.php

Myth 15: Concepts about Nitrification, Stocking Orders, and the New Tank

 

-hank

[MrAnderson]

Here's the original: http://www.reefkeeping.com/issues/2004-01/eb/index.php

Myth 15: Concepts about Nitrification, Stocking Orders, and the New Tank

 

-hank

 

this hobby is hopeless. borneman's description of bacterial growth kinetics is completely wrong.

 

bacteria can thrive and metabolize without reproduction, any undergrad who has taken microbiology could describe a rudimentary growth curve for a population of bacteria, and the accompanying balanced and unbalanced growth. it's called STATIONARY PHASE eric. he just completely makes up his own version of growth kinetics in relation to the equilibration of the nitrogen cycle in that article.