Phospates from raw shrimp?

[Kurt_Nelson]

Originally Posted by tecwzrd

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!