QT and Biofilm

[Brew12]

I've been doing a lot of research lately regarding QT and biodegradation of medications, and feel I now have enough information to start a thread on the subject. In short, I believe heterotrophic bacteria can build up in anaerobic regions of a long-term QT and eventually break down the medications we dose into the water. The sole exception to this is copper, which is not a true medication and thus cannot be biodegraded.

I first read about this here, regarding the degradation of formalin in saltwater: http://www.jzar.org/jzar/article/view/131


Next up is this, Praziquantel degradation in marine aquarium water: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4824874/


The study later discusses how microbial populations (bacteria, protists, algae, phytoplankton, cyanobacteria etc.) may be able to utilize prazi as an energy source after the first exposure to the drug. It also had this to say about the "Biofilm" in a marine aquarium:


A biofilm is any group of microorganisms which stick to each other and then adhere to a surface. Think bacteria sticking to the glass of a QT. Next up is this email exchange between @AlanM and employees of "The Seas", a Disney aquarium:





Conclusions: In light of this information, I feel it is unwise to maintain a long-term QT. Especially if you are using Prazipro, CP, metronidazole, antibiotics, etc. The concern here is that after awhile heterotrophic bacteria (and other biodegraders) will form a biofilm in the QT which will render the aforementioned treatments ineffective. This also explains why the use of medications in a DT environment (full of microbes) often fails, and why it is so important to only use meds in a sterile QT.

A practical solution to this problem is to periodically break down your QT, clean everything using vinegar and then allow to air dry thoroughly before reusing in order to sterilize.

Dosing chlorine, or one of the other chemicals mentioned, may eliminate some of the bacteria but NOTHING kills bacteria 100%. Unless you drain and allow to air dry thoroughly. That will sterilize only because you are (essentially) eliminating their environment.

For those who wish to disinfect using chlorine, here is a good dosing chart: http://dec.vermont.gov/sites/dec/files/dwgwp/DW/chlorinedosageemergencydisinfection.pdf

IME; it takes about a week to fully evaporate 10 ppm chlorine in a well circulated QT.

Not sure how I missed this. Nice compilation!

 

[Brew12]

I wonder if @bios would have anything to add?

 

[4FordFamily]

Ok this is fascinating and disheartening simultaneously.

My 55 gal qt hasn't been sterilized in well over a year, perhaps approaching two.

It's constantly covered in what looks like cyano but behaves differently and the glass is coated in this and a brown film that doesn't look or behave like dinoflagellates. Sure, I probably DO have cyano but I'm curious if any of this nastiness is cultures (if that's what you call a congregation of bacteria). Humble, would it be helpful for me to scrape some of this nastiness and ship it to you?

Literally I've never broken this tank down.

This would also explain why I feel like prazi is less effective or not effective at all. I was wondering if this was all in my head. Ich and velvet are certainly out of my remaining 180 tang tank but I suspect flukes may still be present although not in large numbers. I can't really pinpoint why other than behavior. Very little typical fluke behavior but I feel like I am more in tune to this stuff than most.

Also, new thought: Wouldn't prazi do its entire work in 30 minutes or so? I feel like I read somewhere that it works very fast and then requires second dose to kill the potential offspring 5 days after treatment. Or am I imagining things?

 

[melypr1985]

Wouldn't prazi do its entire work in 30 minutes or so?

it's about 24 hours or so. It's supposed to stay active in the water for 48 hours though.

 

[gig 'em]

I was hoping to encounter someone like you when I started this thread.

Would wiping the entire QT down with a vinegar or bleached soaked paper towel suffice? Rinse and then let it completely air dry? I just think more people would be comfortable using one of those instead of detergent, Lysol, rubbing alcohol, etc. But if that's how it's gotta be...

I can understand people wouldn't want to use Lysol on a tank without thoroughly cleaning it afterwards to remove any chemical residues. Rubbing alcohol will just evaporate away, but I often rinse it off after its completely dry to remove any possible leftover residues, can never be too careful with impurities in our tank water!

You can also use a UV light to treat the tank for 12 hours, but that's not quite available to most hobbyists. High levels of ozone introduced to the tank will also help oxidize and eliminate bacteria and other microbes in the tank. Also, may not be as readily available to most hobbyists.

We never used vinegar as a sanitizing reagent, but if the bacteria that is consuming meds can't survive a low pH environment, then it should work well enough.

 

[Brew12]

Wouldn't prazi do its entire work in 30 minutes or so?

This is correct.
https://link.springer.com/article/10.1007/BF00926798?LI=true

it's about 24 hours or so.

This is also correct.
http://afs.tandfonline.com/doi/abs/10.1577/1548-8667(2002)014<0230:EOPBTF>2.0.CO;2

It really depends what the target organism is and the mechanism that the Prazi is absorbed.

It's supposed to stay active in the water for 48 hours though.

And I think this is what we are learning with this thread. It seems like PZQ could stay effective in a sterile tank for up to 15 days. In some systems it may only be effective for hours at best. I'm still trying to wrap my brain around this one and the potential ramifications.

 

[brandon429]

ok this is awesome thread.

if we are talking about cycling a tank- bacteria are the most fickle, loss prone and in need of our provisions organisms on the planet. not anything w proceed naturally without api and some fish food.
you lift a rock out of the water to work on it, expect total negation of the bacteria in fact they probably fell off when lifted out of the water. because api said a .25 happened that means we can look at bacteria sideways and destabilize them. cycling threads are about panic reactions to a wholly different take on bacteria.

but in dealing with meds and the same biofilms that co-house nitrifiers complexed we see the real deal

we're trying to kill them and attain true microbial dominance and bleach was ruled out as efficient--->awesome and true. its why TW has 120 pages of people putting bleach in their reef and not recycling.

finally here are some alternate confirmation to our tank cycling yaps

our ghost feeding requirement threads

biofilms catch and hold their own feed, biosponges more like, and they are insulative and convey amazing abilities to bac such that we can't get excess surface area clean of them using anything shy of medical aseptic procedures.

this is as much a skip cycling thread as it is a medication thread. linked to our cycling thread.

 

[Humblefish]

I'm still trying to wrap my brain around this one and the potential ramifications.

Same here. I'm still looking into this, but wanted to put out there what I already knew so, collectively, we could solve this riddle.

I strongly feel anaerobic bacteria are the primary culprits here. When I seed sponges down in my sump (for QT), then I think it's probable that I am primarily culturing aerobic bacteria since those are most likely to be free floating in the water. Anaerobic bacteria are primarily found under the sand bed and deeply embedded in the rock work. I also keep the sponges right where the drains pour water into my sump (thus a high oxygen region); most anaerobic organisms react negatively or even die if oxygen is present.

So my next question is this: What kind of bacteria are packed into Bio-Spira, Stability, Dr. Tim's? Aerobic or anaerobic or both? Do you know? I dread calling these people because they act all annoyed that I want specific details about their products.

 

[Brew12]

So my next question is this: What kind of bacteria are packed into Bio-Spira, Stability, Dr. Tim's? Aerobic or anaerobic or both? Do you know? I dread calling these people because they act all annoyed that I want specific details about their products.

They are aerobic. The only anaerobic bacteria commonly used in the nitrogen cycle convert nitrate to nitrogen gas.

 

[Brew12]

I strongly feel anaerobic bacteria are the primary culprits here.

I'm not seeing this. Looking through the study I don't see anything in their setup or testing that create a zone where anaerobic bacteria would thrive.

 

[bios]

very difficult thread
and an actual problem where scientists are spending time and resources to give a solution
as, those we are discusssing in this thread are actually called emerging contaminants
as Humble says time and action of degradation depends at last on the substance we are analyzing so are very different one respect other
and degradation process actued by bacterias Always fails on many type of pharmacological substances
im not experienced on fish tank degradation process for substacences that Always we use to treat our fishes or corals
but in human fields what happen in the waste water treatment plants where system used since now are based on (live muds )filtration systems
have the result that muds and wastewater have high level of those pollulants so at last are enable to treat them

following is a citation:

In the last years, a lot of emerging contaminants have been detected in

surface water and wastewater effluents. Since their occurrence into the
environment can result in toxic effects on water and human life, their
release should be minimized. Indeed, because of their properties, they

may cause disruption of endocrine systems as well as affect the hormonal
control of development in aquatic organisms and wildlife. These
pollutants are called emerging compounds since they are still unregulated
or in process of regularization.
The effluents of urban wastewater treatment plants (UWWTPs) are
among the major sources responsible for surface water contamination by
micropollutants. Hundreds tonnes of pharmacological substances enter
UWWTPs each year, but they can escape physical and biological
processes thus contributing to widespread environmental pollution.

 

[brandon429]

This thread can easily serve its dual purpose now lol its getting linked to good debate threads here and there:

after considering the materials above, if we take live rocks that never left submersion and were full-on reef'd for years, and withhold feed for 3 mos, do the bacteria die? what about 6 mos no feed?

do the biofilms come off, ever, by any type of withholding?


do only the nitrifiers die within the complex due to feed cessation but the mixed aerobes all competing for resources in the scum layer survive?

Biofilm layer rationale literally controls what the masses do to their tanks. this is the first awesome thread Ive seen on any forum regarding biofilms. all of reef cycling is controlled by the notion

the true nature of bioscum sets the care and access boundaries for our tanks. we can use the info to take better control and less of a back seat to reefing

peroxide may work on slick surfaces to remove bioscums but not 3%, and any percentage up to 35% is horrible at sterilizing jagged reef substrate topology. Since medication tanks are glass and plastic fares usually a good wash in 35% using eye protection and gloves would be a fine prep. any form of abrasion such as bon ami old school soap can make up for using weaker oxidants and still sterilize glass nicely given all other aseptic handling procedures

 

[Humblefish]

I'm not seeing this. Looking through the study I don't see anything in their setup or testing that create a zone where anaerobic bacteria would thrive.

It's mostly conjecture at this point, but I'm working with someone to find citations to back it up.

 

[Brew12]

It's mostly conjecture at this point, but I'm working with someone to find citations to back it up.

Ugh.. I need to put my organic chemistry hat back on at some point for this. Praziquantel is C19H24N2O2. If I remember correctly, aerobic bacteria can break down the hydrocarbons of compounds like this much more quickly than anaerobic bacteria can. The speed at which this breaks down leads me to believe the cause must be aerobic.

Very curious to see what you find.

I love theorizing on things like this, but some times they make my brain hurt.....

 

[klp]

I was thinking along the lines of where brandon429 was going about how long it takes the biofilm to degrade within live rock. Would it be necessary to do an alcohol bath to get rid of it as has been suggested to sterilize. I mean a soak for 30 minutes or more. Is that why so many say do not use old rock because of the closed environment with resultant buildups in the live rock that prove disastrous? That would change our procedures for starting a new tank with live rock. I always thought an acid dip would do it but is it effective against biofilm internal to live rock? Makes non porous man made rock look a little better. Never really thought much about that until now.

 

[Reefahholic]

I really want a spectrophotometer now.

In addition to being able to measure CP in the water; if one were to see a rapid decrease after dosing fresh CP, one could assume biodegradation was occurring and it was high time to sterilize one's QT.

Let me know when you get that 10,000 Spectrophotometer. I need to barrow it. lol

 

[Reefahholic]

I honestly don't understand why people want to keep QT's up after treatment.

I think that they wanna have a cycled tank to have a "Go to QT" for any new fish purchases. Honestly though, that's a bad idea. With post treatment low level antibiotics in the water and possible surviving parasites from previous treatments....just not a good idea.

 

[jeff williams]

Humble fish I now this is a question that can very from set up to set up but in the research you've read did any mention the time frame it took for biofilm to reach a level of this Bacteria were it effected meds?

 

[Humblefish]

Humble fish I now this is a question that can very from set up to set up but in the research you've read did any mention the time frame it took for biofilm to reach a level of this Bacteria were it effected meds?

Unfortunately, it can vary greatly. I'm in touch with a public aquarium who uses CP and has a spectrophotometer to test. First time around it took almost 5 months before CP started to degrade. So, they drained all the QTs, bleached them and allowed to air dry for about a week. Now two months later it's happening again. It might be that the biofilm wasn't completely removed during the cleaning process.

@Reef Fever works for a public aquarium, and I believe had a similar experience using CP & degradation. Hopefully he chimes in.

 

[Brew12]

I've been thinking about the relevance of this using Prazi in a DT. I think snails are they key to making Prazi work in a DT for repeated doses. Snails feed off of biofilms like this. They may be our best friend in keeping meds working in a DT. Not really practical in a QT since most of us use copper which is not snail friendly.