Phospates from raw shrimp?

[Kurt_Nelson]

Hi all,

First off... what a great forum here! I've been lurking for the last three months or so as I've gone through the whole "what do I need, what do I want to buy, what am I getting myself into?!" routine. I'm still a couple weeks off from going "live" with my main 46g tank and starting its cycle, but have started up my 10 gallon QT to get it cycled. Since I'm going to gradually add one fish at a time, I figured I'd go ahead and cycle it with a raw shrimp and leave it running for the next few months. The QT has a Penguin Biowheel 100, 50W heater, bare bottom, and a couple PVC couplings in the bottom. I don't have any filter cartridge in the Penguin at the time - it's just spinning the BioWheel. I figured until it cycled, the cartridge is kinda useless.

So here's my question...

Is is possible to get phosphates into the water via the breakdown of the raw shrimp? I would think the answer is "no", but check this out...

When I checked the water on Day 1, everything was normal: SG 1.023, pH 8.3-8.4, temp 78.3, 0/0/0 for ammonia/nitrite/nitrate, and 0 phosphate (Salifert AND Hagen test). In goes a raw, unprocessed (as far as I know), shrimp to melt away.

On Day 7, I topped off the tank with just a cup or two of water (it's a 10g QT), and rechecked parameters. Everything was the same, except for ammonia at 4ppm, and phosphates at about 1.0ppm (Salifert test). I didn't expect the rise in phosphates, as from my understanding that isn't a byproduct of the shrimp rotting away.

Since I just topped off, I rechecked my source water, and it was zero for phosphates. I rechecked the 15 gallons of stored saltwater in my garage and the parameters matched my tank on Day 1, with zero phosphates.

On Day 15 (today), all parameters are still good, ammonia is at about 6ppm (still no nitrites), and the phosphates are now at about 3.0ppm.

Since I'm just cycling a QT, I'm not too concerned about the high levels of phosphate, I'll eventually get them down through water changes. But I'm scratching my head as to where they're coming from. I've checked and rechecked my source water - nothing measurable there. The shrimp originally were frozen - could they have been processed with who knows what in Thailand (where they supposedly came from!) when they were first caught? Has anyone else ran into this before? Or am I just anal to be testing for Phospates in a QT in the first place! (Yes... I am anal, but I figured it'd be good practice!)

Any insight from the gurus would be appreciated!

 

[austinsdad]

Welcome to the boards at AA.

Not sure at all, but my first thought is that the shrimp was frozen and maybe processed in some fashion or some additive for the freezing process was introduced. I'd also be curious to hear what others think too.

Maybe when you cycle the 46g, you can use fresh, unfrozen shrimp instead.

As far as you beign concerned about testing for phosphates at this point, I think its a good thing that you're watching things like that and thinking. Signs of a good and responsible fishkeeper IMO.

Good luck and stay in touch. We often see new posts, and after the problem question gets answered, we hear from them no more. It's a lot more rewarding for us when those same folks stick around, learn, grow, and are able to help others later from their growing experience.

Ammonia should be starting to go back down now as the nitrites get higher. If you can, maybe throw some rock in there - as much as you can. That way, you can move it to the main later, fully cured. If uncured now, you may extend the cycle a bit, but you'll have a good foundation (other than the bio-wheel -which I know nothing about) for the good bacteria you're establishing now. Base rock if available would work too and is cheaper.

 

[roka64]

WELCOME TO AA!!!

Props for doing a fishless cycle!

Wow! It sounds like you have done some great "lurking". LOL!

As for the phosphates, I would have to agree with austinsdad, the frozen shrimp may be causing the phosphates.

As far as you beign concerned about testing for phosphates at this point, I think its a good thing that you're watching things like that and thinking. Signs of a good and responsible fishkeeper IMO.

Same here!

Good luck and stay in touch. We often see new posts, and after the problem question gets answered, we hear from them no more. It's a lot more rewarding for us when those same folks stick around, learn, grow, and are able to help others later from their growing experience.

Definitely stick around!

 

[Kurt_Nelson]

Good luck and stay in touch. We often see new posts, and after the problem question gets answered, we hear from them no more. It's a lot more rewarding for us when those same folks stick around, learn, grow, and are able to help others later from their growing experience.

You'll definitely be hearing from me again. At some point when I get a fish or two in my tank, I was going to write up a "lessons learned" post so others can learn from things I might've done differently. I guess the first lesson was that when your five year old girl asks for a goldfish, your first response shouldn't be "Wouldn't you rather have a 'Nemo'?" until you fully investigate the costs of a saltwater tank! Oh well... deep down, my wife and I have wanted a SW tank for years so it was a good excuse!

Back to the phosphatey shrimp... I still have a left over one from the batch I threw in the QT sitting in my freezer. I think I'm going to stick it in a cup of fresh water (checked beforehand to insure no phospates) and then check the water after a day or so, and try to confirm that the phosphates are coming from the shrimp. I'll let you know what I find out.

 

[austinsdad]

I guess the first lesson was that when your five year old girl asks for a goldfish, your first response shouldn't be "Wouldn't you rather have a 'Nemo'?"

Spoken like a wise parent.

Good luck. Be talkin' to ya, and we're all looking forward to your lessons. 8)

THX

 

[tecwzrd]

Welcome to AA Kurt

Any food source will introduce some po4 to a tank. Frozen food IME is one of the smallest contributors especially if it’s properly thawed and rinsed before adding to a tank.

The general rule for starting a cycle using raw shrimp is 1 small shrimp per 30 gal and the one shrimp you added to a 10 gal was probably more then needed although as long as your nh3 doesn’t go over 5 ppm will do little damage.

The problem with using more shrimp then what is needed is it can overwhelm the biological process and end up taking longer to fully cycle, increase your no3 excessively, and if you have lr in the tank during the process can possibly kill off the desirable hitchhikers that come with it.

If a tank is properly fed then the small amount of po4 introduced via food is very minimal.

Keep in mind that the bacteria you culture within your tank will die off within a week or two if an nh3 source (fish/food) isn’t continually being added. I wouldn’t run your tank for months before adding fish/inverts or you will experience another mini-cycle and could loose them.

What size is your main tank? A 10 gal isn’t going to support fish longer then 4” IMO.

Usually I recommend a QT tank that is 35% of the main incase you ever have to QT the entire tank due to infection i.e. a 20 gal QT tank is fine for a 55 gal main tank. Your 10 gal QT would be fine for a 30 gal or smaller tank

 

[roka64]

Welcome back tec! Thanks for the education, as well! I was a little stumped, but now it makes perfect sense!

 

[Kurt_Nelson]

The general rule for starting a cycle using raw shrimp is 1 small shrimp per 30 gal and the one shrimp you added to a 10 gal was probably more then needed although as long as your nh3 doesn’t go over 5 ppm will do little damage.

The problem with using more shrimp then what is needed is it can overwhelm the biological process and end up taking longer to fully cycle, increase your no3 excessively, and if you have lr in the tank during the process can possibly kill off the desirable hitchhikers that come with it.

Ahh... that's probably why no nitrites are showing up yet, eh? Sounds like I should take out Mr. Stinky Shrimp. And here I was thinking I needed more ammonia!

Since I'm just cycling the bare QT (with a biowheel for the bacteria), I'm not too worried about killing off anything with the high ammonia. I don't think the two PVC couplings are suffering too bad, but now it makes sense why the cycle is taking so long.

I understand the tank needs an ammonia source to keep the bacteria happy, and as soon as the QT tank cycled I was going to throw some snails and hermits in there for quarantine so they'll be ready when my main 46gal is done cycling. Yeah... I know some say you don't need to quarantine inverts, but I'm going to play the overly cautious game in starting this tank up. That's just me...

Regarding my main tank, I'm shooting to get about 60 lbs of cured live rock, will run a Remora Pro HOB skimmer with a Magnum 250 HOB filter. Additionally, I'm going to have a Penguin 100 Biowheel on the back of the main tank, probably running without the filter pad. I'm just using it for the biowheel (yeah... I've read all the pro/con discussions here and other places about those!) to have a immediate source of biological media in case I have to start up the QT after I break it down. If it gives me grief, I'll abandon that idea, but that's the plan for now. Let's see... what else is hiding downstairs... oh... a couple MaxiJet 900 powerheads to move things around and a Coralife Lunar Deluxe T5 lighting fixture (36", 196W).

Thanks for the comments about the QT size. I realize it's a little on the small side, but with a 46g main I'm not looking at stocking anything bigger than maybe a dwarf angel. Still not decided on that for sure. Hopefully... by being cautious up front I can avert having to bring it into action in the near future. But if worse comes to worse, I can always get another small QT or a bigger one if I end up having to house everyone at once.

Again, thanks for the info!

 

[BillyZ]

Welcome aboard Kurt!

I'll also add that since the only real place for the bacteria to colonize is your biowheel. That's not a lot of space. As tw mentioned, that much ammonia not only in a 10 gallon, but with only the biowheel to colonize, it's going to be a slow cycle.

What might make more sense, this is just a thought. Wait until you're closer to actually getting fish, then cycle your main with the biowheel and sponge filter for your QT in the main. THis will cycle both and give your QT filter everything it needs for your first fish. You're killing two birds with one stone and since most folks keep their QT sponge in the sump or other area of their main all the time so it's always "Ready" this should work fine for you. When your main is cycled, set up your QT with water from the main and move the biowheel back to the QT and your QT is ready. As TW mentioned, be sure to "Feed the tank" during your first qt so the bacteria still have a food source in the absence of fish.

 

[tecwzrd]

The Mag 250 is a great product IMO. I’ve used the same one for 10 years now and it’s currently in use on my QT. I use a 350 Pro on my main without any filters/media inside and just use a sponge filter on the intake to keep larger particles from clogging the bio-wheel. I rinse the sponge filter off about once or twice a week. I also like the ability to transfer the wheel to the QT for “instant” filtration but Billy’s idea works just as well if you don’t have bio-wheels.

As you are probably aware 60 lbs of lr should be sufficient for all your biological filtration needs and you could do away with the bio-wheel. I have plenty of lr to run without the bio-wheel also. I’ve run my tank for months with/without the wheel and only noticed a slight variation in no3 levels (slightly higher with the wheel on).

I do large 20% pwc weekly so the no3 has never been an issue for me though.

Great skimmer and lighting Glad you QT your inverts as well. It’s rare but they along with corals occasionally can infect a tank.

Personally I keep my qt tank at the same level as the lfs (ph 8.0 sg 1.019) and slowly raise the sg/ph to the main sg/ph of 1.025/8.3 over the course of 3+ weeks per first & second articles in advancedaquarist.com.

The use of a refractometer is highly recommended while performing any sg changes whether if it’s matching lfs sg level or main sg level to the qt tank. Adjusting the sg down is less stressful to fish coming from that environment and slowly raising it a little bit every other day gives them time to adjust.

 

[Kurt_Nelson]

As you are probably aware 60 lbs of lr should be sufficient for all your biological filtration needs and you could do away with the bio-wheel.

Yup. Like you, the biowheel is only there to provide me a quick way to establish the QT without dealing with the sponge hidden away. I went with the Magnum250 to have the ability to run a polishing filter now and then, and run some activated charcoal.

Personally I keep my qt tank at the same level as the lfs (ph 8.0 sg 1.019) and slowly raise the sg/ph to the main sg/ph of 1.025/8.3 over the course of 3+ weeks per first & second articles in advancedaquarist.com.

I was thinking I'd do the same, but started with a higher SG at this point since it's easier to dilute down the SG during a water change just prior to adding whatever goes in.

The use of a refractometer is highly recommended while performing any sg changes whether if it’s matching lfs sg level or main sg level to the qt tank.

I've got the Sybon refractometer, and love it so far. I'm an old (?) homebrewer so I know the difficulties of reading normal hydrometers and the swing arm boxes look like not a lot of fun, so I never gave the refractometers a second thought. Well worth the money for the piece of mind.

I know I'm probably getting a little ahead of myself by cycling the QT at this point, but figured I might be able to shave some time off the eventual introduction of critters into my main tank if I was quarantining them at the same time my main tank was cycling.

 

[Kurt_Nelson]

OK... I did some more testing and figured I'd report back to make an ending to this post.

I'm pretty sure it was the shrimp that spiked my phosphates. As a test, I took a half of one of my left over shrimp from the bunch I'd bought that I'd stuck in my freezer. I thawed it, and plunked it into a glass of fresh water. I'd say I had 1/2 shrimp in about 12 ounces of water. The water tested 0 to just a trace of phosphates (just a mere hint of blue with the Salifert test) before the shrimp was added.

After just 24 hours of the shrimp sitting in the 12 ounces of water, I tested again. Wow. I didn't know that Salifert test could turn that blue! Off the chart. I used a Tetrafin phosphate test that I had (that I don't like because it's just not very sensitive at lower ppm levels like the Salifert is) that measures up to 5ppm. Off that chart too!

Now granted... I've got a half a shrimp in 12 ounces of water so my concentration of phosphates in the water is no where near what it would be in even a 10 gallon tank. I'm waaaaaayyyyyy more concentrated with my test method. However, there's no arguing that the phosphates are coming from the shrimp, and at a pretty good level only after 24 hours.

Next time I find real fresh shrimp - like directly from Bubba Gump's boat on the dock - I think I'll repeat the test. I'm guessing that there's probably phospates in whatever they spray/coat/dip the shrimp in to make it stay fresher longer.

Folks might want to consider this when they get their shrimp for their cycle - even if the shrimp looks fresh, it probably has been previously frozen somewhere along the route. And if it has, it's probably been given a spritz of something to help it out. So if you find phospahtes somewhere after your cycle, and your water tests fine, don't pull your hair out trying to find the source. It's probably gone already!