Oyster Reef Ecosystem Tank

[Subsea]

Your tank rocks. For viewing at night, I use red LED, the critters can't see it. I have a separate blue LED for viewing phyoto luminance. Corals take in blue light as a high energy input and reflect back green as a lower light energy.

[Michael Hoaster]

You're getting a bunch of good videos done!

I would have thought the tunicate and barnacle would have had plenty of food, I'm guessing DOC. Maybe they need phytoplankton as well. I add phyto every few days and sodium silicate every other day for my sponges and tunicates.

[Chasmodes]

Thank you Michael. I think that I'll wait to stock tunicates and barnacles until the 100 gallon is established. But, I think that you're correct. There was enough food in there.

Update: In my 20g high, the largest blenny, that I thought was a female, revealed the blue spot on his dorsal fin, finally. The spot is hidden with a dark border, but when the light hits it right, it glows. That fish doesn't flare his dorsal fin much, at least until recently. He's king of the tank. The next largest blenny doesn't seem to have a spot, so I think that one is a female. The second biggest one doesn't really flare the dorsal too much, so it is hard to tell if a spot is there. The base coloration is totally different than the larger one. Although, there is a bunch of variation between all of the individual specimens. There is another small female, and the rest are males as they display their bright blue spots all the time. None of the blennies have shown any spawning behavior yet. They're pigs. All they want to do is eat. That said, the largest blenny seems to finally hang around one particular oyster shell for long periods, defending it. But, often abandons it in search of food. He chases all fish away from that shell, but it's hard to tell if it is because he is defending the shell, or just showing them all that he is the boss.

As far as the Ulva in the tank goes, it's doing well. I feed these fish heavily, so there are plenty of nutrients in this tank. That might explain why the sea squirt and barnacle expired (too much ammonia?). I don't think it was for lack of food, at least this time. I also moved them so I could observe them, possibly upsetting their environmental needs. They were alive and well before I intervened. I performed a water change after testing the water. There was a trace amount of ammonia, some nitrates and 50 ppm or so of nitrates. Out of about 30 grass shrimp in this tank, only about 10 remain at most, maybe less. I think the missing ones have been eaten. A couple jumped out of the tank. The grass shrimp in this tank hide a lot in the Ulva and Gracilaria, for obvious reasons, so it's tough to get a count. In the 20g long, where there are subadults and juvenile fish, the grass shrimp are always out and about.

It's tough to tell what sex the fish are in the 20g long as those fish don't seem to have any spot on the dorsal, but they're still a big small, I think. Maybe they haven't developed that coloration yet? A friend of mine who is an expert on Chasmodes says that they develop the spot early in life. If that is true, then my 20g long most likely the fish in that tank are all female. I performed a water change and cleaned out a bunch of cyano. Water parameters were zero for ammonia and nitrite, 30 ppm for nitrates. There are at least 8 grass shrimp out of about a dozen that I placed in there. I know of one jumper, the others may have been eaten.

The killifish seem to do a courtship wiggle or dance often. I don't know if they've deposited eggs or not. I haven't seen it happen nor have I seen any on the vegetation, although with the appetite of those fish, I doubt they'd last long enough for me to see them.

[Michael Hoaster]

Moving your barnacle and tunicate may have been the culprit. I know that sponges are very particular about their orientation to the current. Are you planning to keep live barnacles, oysters, mussels in the future? If so, do you know what their needs are?

You've got quite the fish soap opera going! Who needs store-bought fish!

[Chasmodes]

Well, yep, I have a lot of studying to do. It wasn't really in my plan, but now I'm interested in trying to keep filter feeders alive. I changed their flow and lighting, and I'm pretty sure that was the problem. I noticed that both closed up whenever fish were nearby. If the fish were nearby often enough, they'd never be open enough to feed effectively. That's my theory anyway. Also, the oyster shell that the barnacle was on became infested with hair algae to the point that it may have made it difficult for it to feed.

Originally Posted by Michael Hoaster

You've got quite the fish soap opera going! Who needs store-bought fish!

Yes, that's a great analogy! I learn something about their behavior each day. I had some doubts about keeping this many benthic species in a limited environment (even 100 gallons). But, what I've learned are the following:

- If the fish can handle the nutrient load of feeding them, then they seem to "get along" just fine. They do chase each other, even a little fin nipping. But, the picked on seem to heal up fast, and sometimes fight back. After they get chased, they don't hide in a corner of the tank or behind a filter, they go about as if nothing happened. This is true for all of the species in the tank.

- After my last collecting trip, all of the blennies and gobies came from one oyster box that is smaller than my 20 gallon tank. I'd say that they can get along just fine in a small tank environment based on that alone. I read so many posts about people worried about multiple blennies in a tank. I suspect that it depends on each species, but these are pretty aggressive carnivorous blennies, and with enough specimens to "spread the love", nobody gets picked on more than the others.

- Lots of hiding spots is the key, including good escape routes. These escape routes can be crevices in rock (in my case, between oysters in the cultch), through a mat of macroalgae, or within a hiding spot.

- Sometimes when a blenny gets chased, it simply spins does a lap around an oyster shell enough times that the fish doing the chasing either gives up or loses interest.

- Skilletfish are fearless. But, I'd say that all of them are not really afraid of each other.

- I was worried about mud crabs being a threat to the fish. After watching them around the fish, I no longer fear that as an issue. Blennies, gobies and skilletfish often land on them with no reaction from the crab, except sometimes they shoo the fish away with a claw, but do not try to pinch the fish.

- Grass shrimp live much longer in these tanks than I ever imagined. I thought that they'd be all eaten within a week. I'm pleased about that.

[Michael Hoaster]

Yes, I think it would be cool to at least give those filter feeders you can collect a try. They would be another great addition to your 'oddball' tank concept!

I do think your stocking levels may be a tad dense in your temporary tanks, but that shouldn't be a problem in the big one. Plus you're learning how densely you can get away with, and how to ameliorate any issues, with hidey holes etc.

How big do your crabs get? What do they eat? From what I've read about crabs in general, their biggest threat is at night, when fish settle down.

That's cool your shrimp are making it. In my experience, small shrimp added BEFORE the fish are safe (usually). Shrimp added AFTER the fish are food.

[Chasmodes]

Thank you Michael for your input, always appreciated.

Both species of these mud crabs get about 3/4" across tip to tip of the shell. That's about it. I think as the blennies grow to adulthood, the threat of being eaten is the other way around!

As far as the shrimp go, most of them were accidentally collected with the macros. The way that I look at it is, if they live as inhabitants, great. If they become food, great too, because I can get a bunch each time that I go collecting!

So far, the tank is overpopulated and overfed, but the fish seem very happy and energetic and healthy. Also, I'm doing regular water changes and watching parameters, so I'm sure that helps. As far as inverts go, in the big tank, things should improve. It is just over 100 gallons and an additional 45 gallons if I plumb the sump in. Plus, the lighting is much better and should support all of the macro growth that I could ever want.

Oh yeah, forgot to mention. The white spot on the left side of the big (female) killifish was there for about two weeks. I didn't treat it at all since the fish wasn't distressed due to it aside from a little scratching now and then. Yesterday, I noticed that the spot has completely disappeared.

With regard to your comment on your thread about starting from the ground up with that tank...I most definitely will do that! Your advice makes perfect sense. Being fairly close to their natural habitat is a great advantage in that regard too. These tanks were a bit rushed to set them up, so I'm adapting as I go. Still, if these tanks succeed, then I'm confident the larger system will be that much better.

[Michael Hoaster]

I'm stoked! Can't wait for your masterpiece to be unveiled!

[Chasmodes]

Quick update:

Both tanks seem to have an increase in itching/scratching behavior. I don't see any visible parasites, but that doesn't mean they aren't there. It's hard to get a good look at them anyway because they move around so much. In fact, I'd say that there likely have been parasites in these tanks all along. All of the fish have scratched a little since the beginning. It's just more frequent now. So, what to do.

My assumption is that the culprit is Cryptocaryon irritans simply because freshwater ich doesn't seem to tolerate any salinity. From what I've read, C. irritans doesn't care for freshwater, so my initial plan is to reduce the salinity and perform a long term hyposalinity treatment.

Currently, the sg is 1.016. I plan to reduce it to about 1.009 and keep it that way for several weeks for each tank. I'd like to have these fish healthy by the time I get the big tank set up.

These fish are very hardy, so I don't anticipate any problems. The shrimp should be OK, as they are commonly caught at a lesser salinity than what I'm doing. My guess is that the mud crabs will be OK too, but I'm not 100% sure. I doubt the Ulva will make it through the process, but we will see.

[Michael Hoaster]

Hypo salinity sounds like a good call. You may also want to look at the Tank Transfer Method. Although, with my current knack for killing fish, I'm not a reliable resource in the fish disease arena. So, you may want to employ the 'costanza method', where you do the opposite of what I do…

[McPuff]

Originally Posted by Michael Hoaster

Hypo salinity sounds like a good call. You may also want to look at the Tank Transfer Method. Although, with my current knack for killing fish, I'm not a reliable resource in the fish disease arena. So, you may want to employ the 'costanza method', where you do the opposite of what I do…

I do agree that TTM is going to be your best bet. But then you have to be ready with a new display system and that is the rub. I don't see another way to ensure you rid your fish of ich for the long haul. I'm sure they did have parasites coming in, but in the wild it wouldn't have been too damaging for them. Obviously now, the parasites can get out of control for each fish. Argh, such a pain. That said, TTM is very easy and doesn't really require a lot of equipment/supplies, especially for smaller fish like you've got. Use a 5 gallon tank/container at largest.

[Chasmodes]

Thanks Michael and McPuff. I am going to try the hypo treatment first, simply because catching the fish and removing them to do the TTM might be very difficult, given the structure that they can hide in.

However, I've been thinking about how I might be able to pull off catching them and trying TTM, if I have to go that route. Since we've been hand feeding the fish in the 20g high and they're very tame, food and a net might be enough to catch most, if not all, of them. The fish are a lot more wary in the 20g long though, and those fish will be tough to catch, so hypo most likely is the way to go.

The good thing is that these fish face these types of salinity swings in the wild and are very hardy. Plus, I'd like the sand and oyster structures to be disease free. The change in sg isn't as bad as going from full sea water to a hypo state. I'd be reducing from 1.015 to 1.009 sg. From what I've read, that should do it. One of the problems reefers face when trying to use the hypo treatment is that inverts can't take the treatment, and lowering sg to 1.009 isn't possible, so eliminating parasites is very difficult. And, some fish can't take that type of treatment either.. I don't have corals or sensitive invertebrates to worry about.

Worse case scenario, if hypo doesn't work, I can fall back on the TTM.

Another thing, if I can pull this off, then I'll be confident that I can transfer the sand and oyster structures to my main tank disease and chemical free. And, I'd have an effective QT system in place for future collections. All I'd have to do is keep the QT hypo tanks running all the time, maybe with one hardy specimen (a killifish, for example) to keep the tank's biological filtration up to speed.

[Chasmodes]

Last night, I dropped the sg from 1.015 to 1.010. The fish behavior changed big time in many ways. First, all of the blennies and gobies went into hiding, including one blenny that spent the night against the glass at the filter intake. All of the other blennies hid in oyster shells. The skilletfish either hid or stuck to the glass, not much different than before. The killifish pretty much behaved the same and even kept feeding.

I think that it had an immediate effect on the parasites, maybe not killing them, but agitating them because all of the fish scratched even more than before (and that was a lot of scratching before).

This morning, nothing changed, all of the fish still hiding and the killies doing the same thing. I was a bit concerned about dropping it too fast that I might have hurt the fish. So, this morning, I tried to feed them thinking that if they perked up and ate, all should be OK, and if not...not sure what I'd do.

So, I fed them a block of frozen mysid shrimp. All of the fish perked up and ate, and many of them took the food right from my hand. They foraged a bit and then they went back to hiding.

The grass shrimp seem unaffected.

So, I'll continue at this sg for a week and I might drop it one more point if all goes well.

[Michael Hoaster]

It sounds like you may have shocked them a bit, with the rapid drop in SG. Luckily, going down is much easier on them than going up. Lower salinity actually makes it easier for them to osmoregulate. Bringing them back up should be done much slower for safety. Good luck!

[Chasmodes]

Originally Posted by Michael Hoaster

It sounds like you may have shocked them a bit, with the rapid drop in SG. Luckily, going down is much easier on them than going up. Lower salinity actually makes it easier for them to osmoregulate. Bringing them back up should be done much slower for safety. Good luck!

Yeah, that's probably what happened. I did it over the course of 4 hours per the instructions of what I read, but looking back, should have done it a little slower. I stopped at 1.010. I went back and re-read the article, and it says to go as low as 1.008. I may do that, but over the course of a few days after a week of them getting used to this level.

You're right, bringing it back up should be over the course of several days. I was so happy to see them come up and eat though!

[Chasmodes]

Also, their behavior may explain why I had a hard time catching blennies at one of my spots where I found plenty of them a week earlier (and a week later). We had a lot of rain that week. I always thought that they just went to deeper water (followed the salt wedge), but I bet that all they do is hunker down in their oyster shells or other cover.

[Chasmodes]

Well, while attempting hyposalinity treatment in my 20g high, I successfully killed off...

...two skilletfish and all of my blennies. The last skilletfish may or may not be alive. There are at least three gobies still alive, not sure of the other two. The mummichogs are both doing well, as they are the only fish that are feeding. My guess is that the gobies and the remaining skilletfish won't make it.

The symptoms were, especially with the blennies, that they stopped eating, were swimming constantly against the glass trying to stay at the surface, breathing heavily, eyes were sunken in, and they kind of wasted away. I tried to spot feed them and it worked for a bit, but then they stopped trying to eat even then. It was as if they were blind.

I performed water changes to keep the ammonia and nitrite down...not sure what happened. Maybe dropping the SG too fast caused osmotic shock, or perhaps there was an inadvertent drastic change in pH that I didn't know about. I didn't test for that, but that might explain a lot. Anyway, I'm bummed out big time.

In an attempt to save them, I started the slow process of raising the sg again, but ran out of time. I'm only up from 1.010 to 1.011 now. I should have studied a bit more and may have prevented this from happening.

The 20g long is doing very well, no signs of parasites, although I suspect that they're in there.

I really didn't want to even post about this, but perhaps someone will learn from my mistakes too. Therefore, I have no choice but to learn from my mistakes and move on with my project. I assumed way too much. I couldn't stand to see them scratching so much as they seemed like they were suffering. In retrospect, they were much happier prior to my treatment attempt. I've done more research on this treatment method since, and if I attempt it again later, will follow those protocols closely.

Perhaps the TTM method was the best choice after all. My only reservation on doing that was how to catch all of the fish and get them out of all those hiding spots...not easy at all.

[Michael Hoaster]

Sorry to hear of your losses. Obviously, I feel your pain. We were in the same situation, not being able to catch all our fish, which limits what we can do, disease-wise.

It really does suck to confess to fish deaths, here on RC. I've done it a lot lately. Thankfully, most folks are very supportive. Who among us has NOT killed fish?

Of course the key is to learn from it. How will I prevent this in the future? For me, it will be strict quarantine, with bleach sterilization between treatments, so nothing passes from one to the next.

I think it also helps to focus on what went right. Although it's not exactly a huge victory, I am very happy I managed to save one gramma.

[Chasmodes]

Thanks Michael. You are 100% correct. We've all lost fish, and it sucks to bring it up on forums like this. I guess what bothers me the most this time (compared to other times that I personally lost fish) is that it was a direct result of something that I did.

I know that the fish had parasites, but I don't think that was what caused their deaths. But, I also knew that if I did nothing, they'd eventually die from parasitism.

My lesson learned here is twofold, put quarantine procedures in place for the future (TTM method implementation perhaps), and also be much more careful when I implement a hypo treatment (if I go that route), and to make sure that I check multiple sources for how-to info and also look for posts about results (successes and failures), to cut that learning curve and perhaps save my fishes lives.

[Chasmodes]

oh, and it really sucks because I loved those fish, and miss them already. I feel like I did them wrong even though I know that my intentions were good. I owe it to my other tank inhabitants and also any future fish that I collect to do a better job.

[McPuff]

Originally Posted by Chasmodes

oh, and it really sucks because I loved those fish, and miss them already. I feel like I did them wrong even though I know that my intentions were good. I owe it to my other tank inhabitants and also any future fish that I collect to do a better job.

To me, this is the hardest part. I feel badly for the fish when I have one that dies, regardless if it is my own fault. Sorry that you had those issues. You will come out better for it I'm sure. Life's a garden... dig it. :0)

[Chasmodes]

Thanks McPuff.

I lost another skilletfish. The gobies aren't eating and I expect them to die. Other than not eating, they're behavior is a lot more normal than the other fish that passed away so maybe they'll pull through. The parameters look good, nitrates and ammonia zero, ph is OK, and the sg is 1.012. I'll raise it a point over the next two days.

What is weird to me is that the sudden drop in salinity to 1.010 from 1.016 that I did is far less drastic than some of the hypo treatment techniques that I've been reading about, specifically dropping wild caught marine fish directly into a QT tank at 1.008 sg. So, I don't think that caused the problem, but perhaps it was a pH issue, or maybe I waited too long and the disease was further along than I thought. They were scratching a lot, all of them.

Regarding hypo treatment, I've oversimplified a bit, there are lots of things other than sg to consider when doing it, and I wasn't aware of all that. So, this still could have been my fault. I just need to be much more careful next time. I think that I felt desperate to help them, and that actually was worse than if I had been more patient and read up a bit more about it.

My other tank is doing very well, no signs of scratching behavior. I haven't changed the sg on that tank. I have some cyanobacterial bloom still to deal with, but no biggie.

[Chasmodes]

Emotional roller coaster ---> going into one room and working on and viewing the tank of death, then, heading into the other room to feed the tank that is thriving. This is the preferable order, because the 20g long is such a fun tank to watch and lift up my spirits.

In the 20g long, most of these fish respond to hand feeding. However, they're much more spooky than the adult fish were, especially after feeding. I kind of like that because they tend to behave and forage as they normally would in the wild. It's fun to watch the fish move in and out of the oyster cultches, forage, investigate, spar over temporary territory, establish or maintain the pecking order, and even try to figure out where the crabs are. I also found it difficult to count the numbers of each species as they're always moving in and out of hiding spots. A blenny can literally disappear into a hole in the structure on the right side of the tank and move nearly undetected through that structure and other bottom cover to the other side of the tank. Never a dull moment with this tank.

My only challenge with this tank is the cyano and keeping macros alive. In the death tank, the Ulva and other macro are doing fairly well. A comparison, in the 20g long, Ulva died off in about a month. In the 20g high tank of death, the Ulva has had very little die off and I collected a lot of it.

I really thought long and hard about the future of this project, how to be more careful, and what I can improve on. Until then, keep up on my water changes and test often.

Another goby died in the death tank. Three left, I think. The two killifish are fine. I noticed that one of the mud crabs survived, as did many of the shrimp.

[Michael Hoaster]

I don't think your rapid salinity drop killed your fish. I think it was the ICK. I remember thinking when you first mentioned the scratching, that it starts out so slowly that it tricks you into thinking that they'll be fine. That's what happened to me! In the confines of aquariums, ICK grows exponentially, hence the slow start then rapid devastation.

One thing I've learned from both of our experiences is that no fish is bullet-proof.

I look forward to more back-patting posts and less consoling ones! Onward and upward!

[Chasmodes]

Thanks Michael.

...makes sense. I think my way forward is to gradually reduce the salinity and finish the hypo treatment, but do it more carefully. I want the parasites eradicated. Plus, I want the oyster cultches and anything that survives to move to the big tank parasite free.