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EMeyer

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Posts posted by EMeyer

  1. Shameless hijack!

    After Micah gets his rocks, I'm also in the market for real dry rock (exactly like he said -- nothing mined or manmade). The rock in this thread looks great, you guys have been hoarding some treasures in your garages. 

    Prefer to avoid PDX area at all costs, please PM me if anyone has some real rock they're willing to ship (flat rate is cheap)

    • Like 1
  2. When these things come up I remind myself there are people who buy jeans that cost as much as my mortgage payment and sincerely consider them to be a good value. 

    Its interesting, it seems this is more general than just corals. Human beings can apparently have two very different psychological responses when they find items priced 10 to 100 times above functionally equivalent alternatives. 

  3. Thats an important question. But actually the test relies on eDNA - environmental DNA in the water itself. A large fraction of my data comes from fish, snails, crabs, and corals, none of which make it into the sample. Just their DNA :) Turns out aquarium water is full of DNA. 

    (What I am describing here is different from the standard microbiome test, which relies largely on intact bacterial cells captured on the filter)

    But yeah, sensitivity and positive controls are my main challenge. The test itself is pretty easy. I'd like to take a fish with known symptoms, put it in a tested and confirmed disease-free tank, then sample the water and detect the parasite. Easy peasy except for the part where I need to get my hands on a fish with a disease.

     

    • Like 1
  4. 7 hours ago, Blue Z Reef said:


    You been to Petco bro?????? 🤣

    So you would think! Its all fun and games til you actually start visiting petcos looking to buy fish with symptoms. I find lots of unhappy fish in shitty tanks, but no fish with clear symptoms (e.g. white spots). 

    But I imagine petco moves a lot of fish, probably I just have to keep going back. 

    The bigger surprise has been learning that no hobbyist anywhere in the Pacific Northwest has experienced any fish disease symptoms in their tanks in the past year :)

  5. Im an SPS noob compared to many on the forum, but I'll chime in. 

    Your parameters seem good to me. Happy to see an alkalinity near natural seawater, I think high alkalinity is one of the underappreciated coral killers in our hobby. 

    The other ingredient that I havent seen mentioned yet is an established microbial community. IME most reef keeper find success with SPS in mature, established tanks with good microbial communities, while very few find success in recently established dry rock tanks. Thats certainly been the case for me. 

    • Thanks 1
  6. 12 hours ago, albertareef said:

    As I expected, an entertaining thread!  You could probably get as many different opinions and approaches to QT as there are reefers in this community.  I do think it is important to make sure anyone buying or trading with you is aware of known issues and ideally your approach to husbandry but, really, everyone should just assume there will be hitchhikers of some variety and treat accordingly based on their own comfort level (dip/QT/?).  While it would be nice to think everyone has the resources to implement a stringent scheme the realities are most likely going to make that impractical or at least unlikely.  Kudos to those who manage to pull it off though as it definitely takes patience and great attention to detail.

    This is kind of an exciting possibility as a way to monitor our systems.  What do you think the "confidence level" is with the current testing protocol and how many of the common diseases are you screening for?

    Good question, and thats why I havent started offering the eDNA test commercially yet. Sensitivity testing is hard when diseased fish are so hard to come by. 

    The eDNA test uses a universal eukaryotic marker, so it picks up everything - fish, corals, snails, etc... and parasites. I've seen all the major parasites so far in one or more samples. 

    Positives are easy - if it's detected, the disease is present in the tank. Since DNA data are digital, theres little or no uncertainty about a positive result. 

    The harder part is negatives -- how confident can we be about a negative result? (This is not limited to eDNA or Ich testing, false negative rates are generally higher for all disease testing)

    Right now I can only say its pretty sensitive, in that it sometimes picks up parasite DNA in tanks without any fish showing symptoms. 

    Sensitivity testing turns out to be hard, because either (a) diseased fish are much rarer in the hobby than I thought or (b) few hobbyists are willing to admit it when one of their fish gets disease symptoms. :)

    • Like 1
    • Thanks 1
  7. For whatever its worth, I don't consider vermetid snails a pest. As far as I can tell theyre ubiquitous in the hobby but have never been a problem in any of my tanks. The kind of suck when you poke yourself on them, but bristleworms have caused me 1000x the pain over the years. 

    If we're gonna call any animal hitchikers a pest my money is on bristleworms (which I hate but also consider ubiquitous and inevitable)

     

    (Not to take away at all from your main question, we probably all consider ich a problem and don't want it in our tanks!)

    I think I'd agree with your premise that the presence of ich should be disclosed. I don't have ich in my tanks either symptomatically or based on eDNA sequencing. One of my display tanks does have uronema present without any fish deaths, and ich and velvet are both also detected in some samples, but I've never detected them in mine. If I found a known parasite like that in my frag tanks I'd probably feel like I had to disclose it or stop selling frags from that tank til it was cleared up. 

    • Like 2
  8. How are the frags and remaining colony doing? 

    I have an experimental medication that specifically kills Vibrio, and have used it to save several Acro frags. For almost a year now I've used it on any acro that STN or RTN. It's saved most, including a few really extreme cases. It has to be used as a dip, which makes it tough for colonies. But great for frags. 

    Message me if you want to give it a shot, I have a lot of it...

    • Like 3
  9. Hi all,

    I have a bunch of Melanarus Wrasses for sale (I have 13, and would like to get rid of at least 10). These fish are fat and happy, 2-3" long. They don't sit still very long so its hard to measure them.

    Each fish has been housed by itself for over 4 months, in an isolated tank that never housed any other fish. So these are pre-quarantined. They eat pellets or frozen food readily. $40 each, If you buy multiple I will make you a deal. 

    I am no expert but based on the number of fish and the variation in markings I am pretty these include both males and females. 

    I find wrasses impossible to photograph because the friggin things never sit still. But here are a couple images to prove I really do have them :) You'll find prettier pictures online, but the fish I have are just as colorful as any pictures I've seen online. 

    Warning, they do eat small snails or hermits. Larger ones are fine but the little ones become tasty snacks. 

    fish1.jpg

    fish2.jpg

  10. Looks like I'm finally ready to start this carbon dosing experiment. Its funny how much time maintenance and testing a little nano tank can take, when there are 12 of them. 

    Decided to modify the treatments slightly, to range from less complex to more complex:

    • ethanol
    • ethanol, vinegar, & sugar
    • my homebrewed DOC (a mixture of partially hydrolyzed polysaccharides)

    This will let me test whether a single carbon source leads to a bloom of one type, while a more diverse mixture promotes multiple blooms. 

    Anyone think I should switch one of those first two for something else? Is there a different carbon source more widely used?

     

  11. 7 hours ago, obrien.david.j said:

    Diversity Action #2 completed last night.   10 gallons of "used" tank water, plus transfer of a ~1yr seasoned 8x8x1" Marine Pure Plate.
    https://www.bulkreefsupply.com/marinepure-ceramic-biomedia-plate.html

     

    Both items were transferred within an hour of removal from the source tank.

    Thanks SunCrestReef!

     

    IMG_4307.jpg

    IMG_4308.jpg

    Whoa, seasoned media and water from the famous SuncrestReef tank, awesome! Cant wait to see your next diversity score. 

    If this follows similar dynamics as in my live rock study the community should be established within 2 weeks after putting the rock in the tank. You've got another sample kit in hand now, right? 

    Thats an exciting experiment because it would be a nice answer for people who want live rock diversity but are concerned about hitchikers...

    • Like 1
  12. Hi everyone, 

    I've written up my experiments starting new aquariums with live rock or dry rock. I've previously described the chemistry part; in this article I analyze changes in the microbiome of these tanks. Here are some of the conclusions:

    Quote
    • High-quality live rock promotes the rapid establishment of a microbial community like established reef tanks.
    • Dry rock does not develop such a community on its own in a similar time frame.
    • Live rock is not all the same, but differs in both microbial communities and biological filtration.
    • Live rock quality is not just a question of microbial diversity, but also community composition (not just how many types, but also which types).

    The article is here. I'll be curious to hear what you think!

    -Eli

    • Like 3
  13. So not only are your parameters rock solid between the two samples, there werent even any large water changes. This makes the changes in several major families in your tank even more interesting.

    Although theyre unexpected I am inclined to believe them, and only wonder why. For comparison here are some of the changes during establishment of an experimental tank with live rock. The samples are about a week apart. So at least for some tanks, microbiomes remain relatively stable and recognizably the same over this time scale. (None of which is to say this microbiome shown is in better health than yours; in fact yours is more similar to the typical community than this one). Even during the dynamic early days of establishing a new tank.

    786245173_tankH.jpg.0e9c380501466808ac3d346e40707187.jpg

    And a figure I've shown before, demonstrating that duplicate samples taken at the same time (A1 and A2) produce nearly identical results. So I think its unlikely the differences result from random errors in estimating the community. 

    496386200_withinandbetween.jpg.98790da5db6148d09d4342c60be7e929.jpg

     So I'm stumped what caused the change but inclined to believe it is a real change in those families... 

    You havent changed anything, and your measured parameters are rock solid. Have you seen any differences in the livestock? (I'm thinking of subtle unreported things like more or less algae on the glass, etc) Its a puzzle... So much for the water change idea in your case, huh!

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