Fallow Period Thread

[ctopherl]

I have seen a lot of people post that they need to go fallow, or that they did "a while back", but not much clarity on how to actually do it, the experience or how it went in the end. I am about to start this process and figured I'd document for others who may need to do so in the future to reference.

Background
My mixed reef has been up and running ~9 months. I have had a lot of fish deaths, usually in groups all dying in quick succession, but never wiping out all the fish at once. I have never seen any clear symptoms that point to a specific disease, so at this point I am just assuming some sort of parasite. The only symptoms I've noticed are inconclusive and "could be anything" - lethargy, stop eating, weirds/slow swim patterns, sometimes labored breathing.

Build
Red Sea Reefer 250 V3 (65g total water, 54g display + 11g sump), 2 AI Prime 16HD, ~60lb live rock, sand, 2 small cheap Tunze powerheads, Ice Cap protein skimmer, small ball of chaeto in one of the sump compartments. Nothing else worth mentioning.

Corals
One hammer, two torches, 4 palys, 3 zoas, 1 xenia, 1 encrusting monti, 1 branching monti, 1 acro, 2 acans, 1 duncan, 1 blasto. Only one of the acans is a "colony"-the rest are frags, but growing. They all seem healthy now except the branching monti-it has lost some color recently.

Inverts
2 cleaner shrimp, 1 brittle star, 3 nassarius snails, 3 astrea snails, 2 turbo snails

Feeding
When I had fish in the tank, I was feeding a few small pinches of Hikari marine S pellets in the morning and some frozen mysis+brine in the evening. I occasionally give the cleaner shrimp and brittle star some tiny chunks of dried krill.

I was dosing Red Sea AB+ 8ml/week and target feeding corals BRS Reef Chili once per week, but have since started dosing AB+ daily. I am almost out of the Red Sea and have some Brightwell CoralAmino to continue once that runs out.

Params
1.025-1.026sg salinity (bounces back and forth), 77-78 temp, phosphates ~5 ppb, nitrates 2-3ppm, alk ~7.8

Plan
I have one fish left in the tank that I am trying to get out but he is being difficult. I am going to surrender him to a LFS when I manage to catch him. Then I will run the tank fishless for 8 weeks. I will post a "starting picture" when I eventually catch him and the tank is truly fishless.

I will put a couple pinches of the Hikari marine S pellets once daily to keep some semblance of nitrifying bacteria running and stop nitrates/phosphates from bottoming out. I will manually feed the cleaners and brittle star some krill chunks 2x per week. I will keep dosing the AB+ daily until I run out, at which point I will switch to the CoralAmino.

I have already been toying with the idea of taking my skimmer offline as it has not generated a single cup of skimmate since I've had it-my theory is that my relentless changing of filter floss catches anything that the skimmer normally would. I change the floss 2x per week and will continue with this pattern but expect them to get dirty much less quickly now, at which point I will reduce frequency.

I currently change 10g of water weekly but I am going to skip 1-2 weeks and keep an eye on the nutrients and corals. My phosphates have been undetectable until this week when I started daily dosing the AB+ and I want to spur on some chaeto growth as it has been lacking-we'll see how it goes.

I'll post weekly pictures, observations (especially of corals), parameter changes and any adjustments I make over time. Hopefully in the end when I'm ready to add fish again others can look back on this thread and learn. If this sounds like a dumb idea that no one will find useful, or anyone thinks of a way to make it more useful, let me know, but I feel like I see a lot of "going fallow, what do I do with corals/inverts?" posts without much follow up.

 

[Jay Hemdal]

You've seen the related thread in the sticky section here?

45 Day Fallow periods

I've been doing some research into the "76 day fallow period". I never heard of that prior to coming to Reef2Reef this past summer. I had always used 32 days as the maximum time for a tomont to remain viable under tropical conditions, and then I would round up to 45 days to help ensure that...

www.reef2reef.com

In your scenario, I'm worried that the tank temperature is too low and that 8 weeks might not be long enough. That is only 11 days longer than the 45 day idea I discuss, but that needs to be run at above 81 degrees. Also from your description, you may have had multiple issues with your fish, and laying fallow is pretty specific at only eliminating obligate parasites: Cryptocaryon, Amyloodinium and Neobenedenia. It probably also works for Brooklynella, but does nothing for Uronema and a whole host of bacterial issues that are facultative parasites.

Jay

 

[ctopherl]

You've seen the related thread in the sticky section here?

45 Day Fallow periods

I've been doing some research into the "76 day fallow period". I never heard of that prior to coming to Reef2Reef this past summer. I had always used 32 days as the maximum time for a tomont to remain viable under tropical conditions, and then I would round up to 45 days to help ensure that...

www.reef2reef.com

In your scenario, I'm worried that the tank temperature is too low and that 8 weeks might not be long enough. That is only 11 days longer than the 45 day idea I discuss, but that needs to be run at above 81 degrees. Also from your description, you may have had multiple issues with your fish, and laying fallow is pretty specific at only eliminating obligate parasites: Cryptocaryon, Amyloodinium and Neobenedenia. It probably also works for Brooklynella, but does nothing for Uronema and a whole host of bacterial issues that are facultative parasites.

Jay

Hmm I didn’t realize the 45 days was specifically at 81. I’m guessing my corals and inverts would not be happy at 81. If I am running 77-78, is the full traditional 76 days necessary then?

Also I thought running fallow was effective for pretty much everything except uronema. Do you think it's a waste of time in my case if I don't really know the cause of death? I just assumed it would be parasitic in nature as kind of a default. What do you see as my options here?

 

[Jay Hemdal]

Hmm I didn’t realize the 45 days was specifically at 81. I’m guessing my corals and inverts would not be happy at 81. If I am running 77-78, is the full traditional 76 days necessary then?

Also I thought running fallow was effective for pretty much everything except uronema. Do you think it's a waste of time in my case if I don't really know the cause of death? I just assumed it would be parasitic in nature as kind of a default. What do you see as my options here?

Right, lower temperatures really seems to make a difference, I’m unsure why. Raising the temp can be rough on some corals, so better to extend the time. I would go for the full 76 days and ensure that all new fish are very well quarantined.
Jay

 

[ctopherl]

Right, lower temperatures really seems to make a difference, I’m unsure why. Raising the temp can be rough on some corals, so better to extend the time. I would go for the full 76 days and ensure that all new fish are very well quarantined.
Jay

Thanks! That is very doable-I was afraid you were about to tell me infinite fallow period length would do me no good.

What are your thoughts on businesses like Marine Collectors who charge a premium essentially offering QT as a service?

 

[Jay Hemdal]

Thanks! That is very doable-I was afraid you were about to tell me infinite fallow period length would do me no good.

What are your thoughts on businesses like Marine Collectors who charge a premium essentially offering QT as a service?

Pre quarantined is better than non quarantined in every instance. Does pre quarantine result in risk free fish? No. I quarantine everything, even fish I get from another public aquarium!
I once sent some cichlids out to another aquarium. I had raised them myself and they had no issues. The other aquarium didn’t quarantine them, whups they had flukes!
Jay

 

[ctopherl]

My tank has been fallow for about a week and a half now. Here is a shot from day 1.

 

[ctopherl]

I have done 1 water change of just under 10 gallons in the last 3 weeks.

Params as of 10 minutes ago:

Nitrates: ~4ppm
Phosphates: 7ppb
Alk: 7.2
Ca: 445
Ph: 8.2
Salinity: 1.025sg

I tested alk a few days ago at 7.8 so I am going to try dosing a little. I have not had to dose anything up until now. I will start slow/small and keep an eye on ph and salinity.

 

[ctopherl]

I have been feeding a pinch of hikari marine S almost every day (skipped probably 3-4 days total). The 3 nassarius snails and 2 cleaner shrimp g after it.

I feed the 2 cleaners and 1 brittle star a little chunk of dried krill 2x per week.

I target feed my corals reef chili once every 7-10 days. I have recently started dosing 2ml Brightwell CoralAmino daily as my nitrates and phosphates historically run low.

 

[ctopherl]

Changes:

* Took skimmer offline. I was debating doing this even when I had fish as it never pulled anything out. My theory is that my diligent changing of filter floss and careful feeding led to not enough “gunk” for the skimmer to be useful.
* As 2/3 of my SPS frags are looking pale, I started dosing the CoralAmino from Brightwell.
* In attempt to let my phosphates get a tad higher, I am trying less water changes
* I will now try dosing a bit of BRS soda ash as my alk seems to be dropping. My Ca still seems in good range so I’m going to leave that alone for now.
* My chaeto is not growing visibly so I increased my fuge light period to 14 hours on a reverse cycle from the DT. If it starts sucking up nitrates and phosphates I will dial it back and/or change my filter floss less often. I am testing nitrates and phosphates 2x per week now to keep an eye on the changes.

Observation:

I am still having to change out my filter floss every ~3 days or so-it gets funky. I’m not sure why since there is no fish waste and much less food going in the tank.

Everything seems happy and healthy except my couple SPS. I’m hoping dosing aminos, slightly higher N/P and dosing some soda ash will help turn them around.

 

[ctopherl]

Reflection:

I am pretty sure uronema is what is taking out my fish. There is definitely uronema in my tank as I had a chromis die with the rashes in there. I wasn’t sure if it was uronema at first since I have had a wide variety of species die (not just the “susceptible ones”) and none of them have developed rashes except the chromis.

Looking back though, it does seem as though my rampant death spells all happened around the time of adding a “susceptible fish” (chromis, anthia) that may have gotten the parasite going.

My plan going forward is to still wait out the 76 days just in case something else is in there as well, then try slowly adding some “non susceptible fish”. If they are ok then I will try uronema management. If I still have issues then I may start the tank over.

 

[ctopherl]

Full tank shot at 2 week mark. Everything seems happy except my couple SPS losing color.

I’ve raised alk to 8.8 dkh over a couple of days and confirmed I am losing about .1 dkh per day. Just dosed a bit more to bring it up over 9 and will let it settle around 9.

 

[ctopherl]

4 weeks in, had to start dosing Ca. I can't tell if it's because my corals are growing and consuming more or because I stopped doing water changes which naturally replenished alk/ca.

My current plan to attempt to get rid of the uronema is to combine a number of approaches that could potentially be successful but are not guaranteed.

* Dumped a bottle of pods in both sump and DT. I see them everywhere. Supposedly pods can eat small parasites like uronema.
* Dosing Metroplex every 48 hours directly into water column for 3 weeks. I will keep an eye on corals and inverts in case there are any adverse affects-this seems like it can be hit or miss
* Once Metroplex dosing is complete, run a 15W Aqua UV sterilizer. There should be about a month left of fallow period at this point. I am debating running it directly off the DT for a month, even though it will be ugly, and then moving it down to the sump when I am ready to try a couple of fish
* Get an aquabiomics test to see if uronema (or any other parasite) is present
* Avoid anthias and chromis

 

[ctopherl]

4 week tank shot. The torches are really blooming and looking full.

 

[Jay Hemdal]

4 weeks in, had to start dosing Ca. I can't tell if it's because my corals are growing and consuming more or because I stopped doing water changes which naturally replenished alk/ca.

My current plan to attempt to get rid of the uronema is to combine a number of approaches that could potentially be successful but are not guaranteed.

* Dumped a bottle of pods in both sump and DT. I see them everywhere. Supposedly pods can eat small parasites like uronema.
* Dosing Metroplex every 48 hours directly into water column for 3 weeks. I will keep an eye on corals and inverts in case there are any adverse affects-this seems like it can be hit or miss
* Once Metroplex dosing is complete, run a 15W Aqua UV sterilizer. There should be about a month left of fallow period at this point. I am debating running it directly off the DT for a month, even though it will be ugly, and then moving it down to the sump when I am ready to try a couple of fish
* Get an aquabiomics test to see if uronema (or any other parasite) is present
* Avoid anthias and chromis

Sorry, I missed this post. Don’t go to any great pains to try and eliminate Uronema, it is best just to avoid problem fish.
Uronema is a falcultative parasite, they normally feed on bacteria and can be isolated from just about any mature aquarium....nobody knows why they cause fish infections in some instances. In all the cases I’ve dealt with, the problem started with a new acquisition of a species known to be an issue. I’ve then had it spread from them to less susceptible species, especially in hyposalinity.


Jay

 

[ctopherl]

Sorry, I missed this post. Don’t go to any great pains to try and eliminate Uronema, it is best just to avoid problem fish.
Uronema is a falcultative parasite, they normally feed on bacteria and can be isolated from just about any mature aquarium....nobody knows why they cause fish infections in some instances. In all the cases I’ve dealt with, the problem started with a new acquisition of a species known to be an issue. I’ve then had it spread from them to less susceptible species, especially in hyposalinity.


Jay

Thanks for the input. I do think most of my issues began when introducing chromis or anthias so you may be on to something. It is still concerning that I’ve had so many deaths in “less susceptible species”. The only somewhat great length is the sterilizer, but it’s just a HOB one that fits in my sump so probably a good idea anyways.

I’m not even positive uronema is the cause of death for any of the fish I’ve lost except one chromis, but due to that chromis I’m pretty confident it’s in my tank.

I hope avoiding susceptible species will make this not a big deal but given how many fish I’ve lost I’m not yet convinced unfortunately.

 

[Jay Hemdal]

Yeah, confirmation of Uronema is tough, even with a microscope. Then, there are a whole group of similar protozoans all lumped under the generic name “Uronema”. I can’t tell them apart, I suppose some researchers can. They are all grouped as Scuticociliates.
Jay

 

[ctopherl]

Another update. Fallow period is going well! I ran about 2.5 weeks of dosing Metroplex to the water column and saw no ill effects with corals or inverts.

Invert feeding seems to be going well as they are still alive and active.

I think I've finally stabilized alk around 9dkh and Ca around 420-430ppm. I only lose about .1 dkh and 5ppm Ca per day so I'm going to try dosing 10ml of each every ~3 days and see where that gets me after a couple of weeks.

My phosphates are really low-I consistently read around 8ppb. My nitrates seem fine around ~4ppm. I am reducing photoperiod on my refugium from 12 hours/day to 9 hours/day and will see if that raises phosphates a bit-my acro is still not happy and I lost a branching monti. At the start of my fallow period, my chaeto was not growing so I turned up the intensity setting on my Kessil H80 from about 50% to 100%-now the chaeto grows like a weed. I expect to have to increase the photoperiod again once I add fish (more food, more nitrates from fish breathing ammonia) so that should be perfect.

I rescaped a bit as the one big "boulder" rock on the left was unstable and making me nervous. This combined with swapping a powerhead out for an Mp40 has allowed me to get decent flow in the tank without decimating the corals so hopefully that helps coral growth as well.

The UV is not running yet as I got an HOB model off BRS and it sounds like a waterfall. I got some tubing to try and suppress the noise and will try to set that up this weekend.

My 77th day is June 29 so I will be talking to a Humblefish-approved preQT vendor about ordering some fish in a couple of weeks.

 

[ctopherl]

Found this interesting post on HumbleFish site discussing hydrogen peroxide dosing to eliminate parasites. I may consider trying this depending on results of another user currently trying this for uronema.

 

[Jay Hemdal]

Found [this interesting post on HumbleFish site](https://humble.fish/community/index.php?threads/peroxide-h2o2-dosing-for-parasites-in-reef-tank.725/) discussing hydrogen peroxide dosing to eliminate parasites. I may consider trying this depending on results of another user currently trying this for uronema.

I was really enthused by the various possibilities of H2O2, so I did some bench testing. I didn't have any current active disease issues to test it on (but that's a good thing!) so I did some basic chemical tests. I haven't read Humblefish's current thoughts on this (I'll look at it in a bit) but some of his assumptions posted here on R2R some time ago didn't stand up to my testing, specifically in regards to not using plastics, not aerating, etc. Here is the link to what I found:

Hydrogen Peroxide Bench-testing

Bench testing of the effects of hydrogen peroxide in aquariums.

www.reef2reef.com

The most important thing I found is that there are now H2O2 test strips (both low and high dose versions) that can be used to actually determine relative activity of the peroxide. I think these are used for potable water testing, but their application is HUGE for aquariums, as peroxide activity is completely dependent on the level of peroxidase in the aquarium, and the only way to know that is through testing.

In regards to using this for Uronema - since that specific issue is intercellular (internal) I do not see how any bath treatment can reach those protozoans to affect a cure. It could have some benefit in limiting the protozoans in the system itself, but once the disease is internal, I can't see how any bath could work. I see that same issue with copper and chloroquine treatments for this problem....they just fail.

Jay