Billy's Deep Sandbed Experiment

[billygoat]

Here is an interesting curiosity that I've been observing in this tank: colonial tunicates. This maroon mat marbled with white spicules is a huge group of them. They encrust over the rocks very quickly, and even overgrow the blades of calcifying algae like Halimeda. 

 

 

Little micro life-forms like this are very interesting to observe. I am happy to see them thriving in my aquarium.

[M. Tournesol]

Super jealous ☹️, my live rock don't have tunicates anymore. Yours have COLONIAL tunicates 😫

[CD_Scapes]

1 hour ago, billygoat said:

Here is an interesting curiosity that I've been observing in this tank: colonial tunicates. This maroon mat marbled with white spicules is a huge group of them. They encrust over the rocks very quickly, and even overgrow the blades of calcifying algae like Halimeda. 

 

 

Little micro life-forms like this are very interesting to observe. I am happy to see them thriving in my aquarium.

I have some gray/white colonial tunicates that seem to be a very annual species. Grows SUPER fast, feeds and then dies out 

[billygoat]

4 hours ago, CD_Scapes said:

I have some gray/white colonial tunicates that seem to be a very annual species. Grows SUPER fast, feeds and then dies out 

I know exactly the ones you mean! I saw them appear in my tank a few weeks after I first added my Florida live rock. A few days later they all disappeared just as quickly, and I haven't seen them since.

 

5 hours ago, M. Tournesol said:

Super jealous ☹️, my live rock don't have tunicates anymore. Yours have COLONIAL tunicates 😫

Tunicates are difficult to maintain in a reef tank, that's for sure. I tried keeping a few solitary tunicates in my 40g reef last year and they didn't do very well. I don't think they get nearly enough to eat unless the water is constantly saturated with food particles.

 

Those colonial tunicates are only a few of the various curiosities that I have seen crawling around on my rocks. Just recently I noticed some small limpets appear, apparently out of nowhere, as well as a tiny chiton. And of course there are the usual live rock suspects: spaghetti worms, bristle worms, eunicid worms that build papery tubes of mucus, beautiful transparent glass anemones, tiny cryptic sponges, bright orange clusters of colonial tunicates (a different variety, much more difficult to photograph unfortunately), strange boring clams, barnacles - the list goes on and on. The random life on my rocks and sandbed fascinates me, sometimes even more than the animals that I've intentionally added to the system. 

 

[billygoat]

It's been a busy week, but I am here with some photos of the tank! Not much to update, which I guess is probably a good thing, but the tank continues to be a pleasure to observe. Here are some pictures of various things.

 

Solitary tunicates, as well as some assorted corals. My experimental SPS frags seem to be doing pretty well but aren't exhibiting very fast growth. The soft corals, on the other hand, are all growing quickly.

 

   

 

Some macroalgae: Caulerpa racemosa (left), C. sertularioides (right), Cladophora sp. (middle). The soft coral at left is a Sinularia, and the purpleish thing at center is a photosynthetic encrusting sponge. The sponge develops interesting oxygen bubbles inside of its tissues during the daytime.

 

 

Anthelia. Some Sargassum is also growing on the rear of this rock but is not really visible from this angle.

 

 

Some views of the tank overall:

 

 

 

This tank is about three months old now. I have gotten my daily feeding and maintenance regimens down pretty well at this point: each day I dose 6 drops of ChaetoGro and 1 drop of iodide supplement. Once every three days I add 5ml of KH solution, and once per week I dose Calcium. Magnesium is once per month or so. I do not perform water changes.

 

The amount of food that goes into this tank is enormous. Each day I feed out a mixture of items selected from my from my huge menu of fish foods: flakes, sinking herbivore pellets, floating blackfly larvae pellets, frozen mysis, frozen gel food, Brightwell plankton supplements, powdered plankton supplements, and various other dried fish foods. I have adopted an approach to feeding that is entirely opposed to what I was taught in wholesale: I feed the tank, not the fish. I try to imagine the system as a single holistic organism, and like any organism, it needs abundant nutrients in order to thrive.

 

I am pretty content with where the tank is currently at, but I do have a few ideas for the future. I am particularly interested in a large photosynthetic clam, as the experimental filter-feeders I've been trying out (tunicates, flame scallops, and a wing oyster) have all been doing well. However I am somewhat concerned that adding such a large, hungry organism would throw off the balance that I have managed to establish here. I also worry that my lighting would not be enough to support a clam in the long term.

 

Anyway, thanks as always for reading! I'll try to remember to update more frequently with some of the tiny details that I love to observe every day. 😁

[DevilDuck]

I think the tank is a good candidate for non-photosythetic stuff, gorgonians, sun coral, dendronephthyam, colorful sponges etc.

[M. Tournesol]

Or a colony of feather duster worms 🤩

[gena]

I see a separate small clump of anthelia on the gravel.  Did yours pop off a head from the main colony like mine did?

[Tired]

Oh, you got sargassum growing, nice! That stuff's neat looking. 

[billygoat]

On 10/1/2021 at 1:17 PM, gena said:

I see a separate small clump of anthelia on the gravel.  Did yours pop off a head from the main colony like mine did?

Yeah, the Anthelia cleaves off super easily, and clearly has no problem growing right over the gravel. I am sure I will have plenty of it to give away soon... in fact I already do! It's huge! 😅 I'm very impressed not just with this coral's growth, but also the size of its polyps - mine are nearly three inches long when they are fully extended! For some reason I was expecting them to be smaller.

 

 

On 10/1/2021 at 10:27 AM, DevilDuck said:

I think the tank is a good candidate for non-photosythetic stuff, gorgonians, sun coral, dendronephthyam, colorful sponges etc.

While it's true that certain filter-feeders seem to do pretty well in here, I think a lot of those things would struggle. 🙁 Dendronephthya for example requires a huge amount of dissolved organic stuff to eat... but also benefits from good water quality, which this tank most definitely does not have. The combination of tons of food + clean water is a difficult thing to manage in a home aquarium, which is probably why you rarely see such animals kept by hobbyists. Heavy skimming would almost certainly be a must.

 

Gorgonians would probably do well though! I might try a few frags in here at some point.

 

Just a short update today! Here are a few pictures from around the tank:

 

 

 

 

I cleaned the glass! Can you tell? 😅

 

 

[seabass]

5 minutes ago, billygoat said:

I cleaned the glass! Can you tell?

Looks great!

[Murphs_Reef]

Yeah I'm ok with this... Looks brilliant 👍🏼

[Pjanssen]

Your macros are looking great.

[gena]

On 10/7/2021 at 1:03 PM, billygoat said:

Yeah, the Anthelia cleaves off super easily, and clearly has no problem growing right over the gravel. I am sure I will have plenty of it to give away soon... in fact I already do! It's huge! 😅 I'm very impressed not just with this coral's growth, but also the size of its polyps - mine are nearly three inches long when they are fully extended! For some reason I was expecting them to be smaller.

I'm going to be in so much trouble before long LOL.  It's growing so fast!  Oh well....a good excuse to upgrade I guess .

[KingOfAll_Tyrants]

On 8/22/2021 at 8:44 PM, billygoat said:

In other news: Cerith snails are amazing. A few days ago I had one crawl out of this tank in the middle of the night (dumb snail) and fall into the space behind the stand. I heard it hit the floor and came over to look for it but could not find it, so I gave up and went back to bed. 30 hours later I discovered the snail jammed into a corner of the room. I assumed it would be super dead after spending more than a day out of the water, but I tossed it back into the tank anyway, just to be sure. Ten minutes later it began to move. How an aquatic animal can survive total desiccation for that amount of time is completely beyond me, but kudos to you, snail. Well done. 🙏

 

Nothing much else to report here, but more to come as things continue to develop and change! 😁

 

Reading through this thread now; will finish reading it, but wanted to comment on this subject:

 

A lof of the snails and the like that we get in cleaner packages are intertidal; I've also had some snails crawl out of the tank and just hang out outside near the tank for who-knows-how long, and upon returning it to water it was fine.   [ETA: and then reading the subsequent posts other people said the same 😄 ]

 

A few other random comments:

 

1. I was impressed by the thought behind this tank, but then saw you have lots of experience, so it's not surprising it looks good.

 

2. do you still dose alkalinity?  I would have thought a seagrass tank would not needed dosing at all (granted that you have some live rock and corals - the growth on the Gulf Live Rock is impressive - and a Millepora fire coal!!!!). [ETA: have you started dosing nutrients, or anything else for that matter?]

 

3. I've been thinking of something similar as basically a display refugium: that is, one tank would be a regular reef (an acro reef for argument's sake) and the connected tank of 50-100% the same size would be a seagrass tank like this.   But thinking about it, it seems that even with a well fed acro tank providing stuff for this, the net nutrient balance might still be too different for such tanks?   

 

[billygoat]

On 10/12/2021 at 2:19 PM, KingOfAll_Tyrants said:

Reading through this thread now

Hi and thank you for visiting! 😁

 

On 10/12/2021 at 2:19 PM, KingOfAll_Tyrants said:

1. I was impressed by the thought behind this tank, but then saw you have lots of experience, so it's not surprising it looks good.

I appreciate the complement! This tank is kind of just a sandbox where I experiment with various things, but I am glad that you enjoy it. It's very interesting to observe, even if it is pretty filthy by normal reef tank standards. 

 

On 10/12/2021 at 2:19 PM, KingOfAll_Tyrants said:

2. do you still dose alkalinity?  I would have thought a seagrass tank would not needed dosing at all (granted that you have some live rock and corals - the growth on the Gulf Live Rock is impressive - and a Millepora fire coal!!!!). [ETA: have you started dosing nutrients, or anything else for that matter?]

My regimen for additives has changed since I last posted about dosing. In the beginning this tank consumed an enormous amount of bicarbonate, but consumption dropped off steeply a few months after I initially set it up. I believe this reflects a change in how nutrients cycle through the system: initially the biofilter in my gigantic sandbed was likely handling most of the organics that I put into the tank and consuming bicarbonate as part of this process, but later on macroalgae (which apparently consume much less KH) took the upper hand over the bacteria and now appear to run the show. There are some corals and coralline algae in here, but consumption from the biofilter definitely dwarfs the amount of KH that those few calcifying organisms consume.

 

Right now I just dose ChaetoGro (3 drops per day) and a very small amount of iodide solution (1 drop once per week).

 

On 10/12/2021 at 2:19 PM, KingOfAll_Tyrants said:

3. I've been thinking of something similar as basically a display refugium: that is, one tank would be a regular reef (an acro reef for argument's sake) and the connected tank of 50-100% the same size would be a seagrass tank like this.   But thinking about it, it seems that even with a well fed acro tank providing stuff for this, the net nutrient balance might still be too different for such tanks?   

Assuming you are not intentionally overfeeding the display portion of such a system, I think it would be difficult to maintain the same kind of algal biomass that you see in this tank. Not to say that you couldn't set up something similar - in fact I think it is a really cool idea! - but the refugium portion of the system would most likely require heavy supplemental feeding or nutrient additives to maintain a lush display of macroalgae. My concern would be that the large amount of macroalgae would be so efficient at removing nutrients that the corals wouldn't get enough of them. But I'm sure that if you tinkered with it for long enough you could get it to work!

[CD_Scapes]

Hey I just saw AddictiveReefKeeping has some manatee grass right now if you wanted to try another sea grass 

[billygoat]

On 10/14/2021 at 7:20 AM, CD_Scapes said:

Hey I just saw AddictiveReefKeeping has some manatee grass right now if you wanted to try another sea grass 

Thank you for the recommendation! I think this tank is headed in a bit of a different direction though. Yet more big changes came through yesterday when my Caulerpa racemosa decided to spore out on me. I had the macroalgae humming along at a good pace for awhile there but the wheels kind of fell off over the past week or so: I ran into some sort of nutrient imbalance/lack of something/simple overabundance of algal biomass without increased inputs to compensate. On top of that, dissolved oxygen was dropping very low at night, which required me to run an airstone during the nighttime, which in turn caused horrible salt creep that was driving me crazy. Long story short: the seagrass is still around (and some of it actually appears to be growing), but this tank is probably headed in a new direction now.

 

Here are some photos from before and after the caulerpa apocalypse. About an hour after lights on yesterday morning the tank looked like this:

 

 

I removed the sludgy caulerpa, performed an emergency water change, and added the HOB filter with floss inside. Thankfully the tank was beautiful again when I came home from work, but it's definitely different without all that caulerpa on the left hand side.

 

 

All of my fish and inverts seem to have survived this episode with no issues, but I am definitely going to be making some changes to this system to ensure that such troubles do not occur again. Stay tuned!

[CD_Scapes]

2 hours ago, billygoat said:

Thank you for the recommendation! I think this tank is headed in a bit of a different direction though. Yet more big changes came through yesterday when my Caulerpa racemosa decided to spore out on me. I had the macroalgae humming along at a good pace for awhile there but the wheels kind of fell off over the past week or so: I ran into some sort of nutrient imbalance/lack of something/simple overabundance of algal biomass without increased inputs to compensate. On top of that, dissolved oxygen was dropping very low at night, which required me to run an airstone during the nighttime, which in turn caused horrible salt creep that was driving me crazy. Long story short: the seagrass is still around (and some of it actually appears to be growing), but this tank is probably headed in a new direction now.

 

Here are some photos from before and after the caulerpa apocalypse. About an hour after lights on yesterday morning the tank looked like this:

 

 

I removed the sludgy caulerpa, performed an emergency water change, and added the HOB filter with floss inside. Thankfully the tank was beautiful again when I came home from work, but it's definitely different without all that caulerpa on the left hand side.

 

 

All of my fish and inverts seem to have survived this episode with no issues, but I am definitely going to be making some changes to this system to ensure that such troubles do not occur again. Stay tuned!

The problem is that the seagrass is taking all the nutrients as well as the DO drops from the seagrass. Normally in a tank that size caulerpa won’t go spore/sexual that often. 

[KingOfAll_Tyrants]

6 hours ago, CD_Scapes said:

The problem is that the seagrass is taking all the nutrients as well as the DO drops from the seagrass. Normally in a tank that size caulerpa won’t go spore/sexual that often. 

What are DO drops?

 

OP: looking  forward to hearing about the new direction for the tank!

 

As for my plans: I think, whenever I can get my tank started again, I will go for two separate tanks. One conventional zeovit 20g AIO; the other will be an experimental seagrass type 20g,  learning from your experiences and from other threads.

 

Theoretically, though, both of these should be high nutrients in, high export tanks?

 

(sidebat: BRS made the almost certainly correct observation but a large coral in itself is essentially a refugium, because it will inevitably absorb a huge amount of nutrients in and of itself:

 

)

 

Anyway, if I can get them both working and stable with similar parameters, I may try to raise (the right species of) acros in the seagrass tank as well. There's plenty of precedent for that in the ocean…

[CD_Scapes]

2 minutes ago, KingOfAll_Tyrants said:

What are DO drops?

 

OP: looking  forward to hearing about the new direction for the tank!

 

As for my plans: I think, whenever I can get my tank started again, I will go for two separate tanks. One conventional zeovit 20g AIO; the other will be an experimental seagrass type 20g,  learning from your experiences and from other threads.

 

Theoretically, though, both of these should be high nutrients in, high export tanks?

 

(sidebat: BRS made the almost certainly correct observation but a large coral in itself is essentially a refugium, because it will inevitably absorb a huge amount of nutrients in and of itself:

 

)

 

Anyway, if I can get them both working and stable with similar parameters, I may try to raise (the right species of) acros in the seagrass tank as well. There's plenty of precedent for that in the ocean…

DO = Dissolved Oxygen

 

 

[KingOfAll_Tyrants]

On 10/17/2021 at 3:13 PM, CD_Scapes said:

DO = Dissolved Oxygen

 

 

Ah, got you.  So you're saying that the nutrient absorbtion from the seagrass, as well as their use of oxygen (?) at certain times of the day make it hard for caluerpa, therefore if you want to keep caluerpa and seagrass (or maybe better to say: keep such a large mass of macroalgae and seagrass) you need to keep the tank very well aerated, and possibly does a LOT of nutrients?

 

 

[billygoat]

8 hours ago, KingOfAll_Tyrants said:

Ah, got you.  So you're saying that the nutrient absorbtion from the seagrass, as well as their use of oxygen (?) at certain times of the day make it hard for caluerpa, therefore if you want to keep caluerpa and seagrass (or maybe better to say: keep such a large mass of macroalgae and seagrass) you need to keep the tank very well aerated, and possibly does a LOT of nutrients?

 

 

Actually the seagrass itself has almost certainly had very little impact on what's going on in this tank. The biomass of the grasses was absolutely dwarfed by the amount of macroalgae in there, so I reckon the real problem was that the macros grew until they consumed all the available nutrients and then could grow no more, at which point they realized they were at the end of their rope and spent the last of their energy trying to reproduce. The seagrasses could never come close to competing with fast-growing macroalgae like Caulerpa, so it was probably a mistake to try and cultivate them both in the same small aquarium.

 

As for the dissolved oxygen issues: basically the more photosynthetic biomass you have in the tank (algae, plants, and the symbionts that live inside of corals and other zooxanthellate invertebrates), the more of a risk there is that dissolved oxygen will drop at night. The reason for this is that algae and plant cells have to respire just like those of animals do, consuming oxygen and releasing carbon dioxide, in addition to performing photosynthesis to make energy (and oxygen as a byproduct). Since photosynthesis only occurs in the presence of light, it stops when the lights turn off... but respiration continues throughout the night, and not just from the plants and such: fish, invertebrates, and other animals all keep on consuming oxygen when the lights aren't on. This can result in a net reduction of oxygen in the water during the evening hours - a reduction which, combined with the overall increase in oxygen levels during the day thanks to photosynthesis, can cause some wild swings in DO. Thankfully it's pretty easy to combat these DO swings by improving gas exchange in the tank, usually by introducing some mechanical means of breaking up the surface tension and mixing the water (e.g. an airstone, overflow box, etc.), Again, macroalgae are more to blame for this issue than true plants like seagrasses are because plants can store oxygen in their tissues to use for respiration whereas macroalgae have to remove that oxygen directly from the water.

 

The TL;DR is that macroalgae will always be the ones making things difficult for the seagrasses, not the other way around. As long as conditions for macroalgal growth are good, seagrasses have no chance of competing with them.

[KingOfAll_Tyrants]

Thanks for the explanation!  yeah that all makes sense.

 

Doing some other reasearch related to this, which brought me to the venerable chucks additction  website - one of those guys from years ago with lots of experience with marine life who can't write into easily digestible sound bites that reflect currently popular concerns and trends - and found his description of (indo-pacific shallow water - IIRC he was living in the Phillippines when he wrote his website; also note there are seagrass and macroalgae species which grow even at mesophotic depths) seagrasses interesting, albeit with debatable direct applicability.  

 

A few interesting gems:

 

Quote

 

Fish, sea turtles, sea urchins and dugongs that graze directly upon the seagrasses, representing at least 10% of their diet, can significantly alter the nutrient and detrital pathways by exporting the nutrients out of the seagrass meadows by swimming away and defecating elsewhere. 

 

climatic and tidal events cause disturbances. These disturbances of the nutrients are yet another important factor in the seagrass nutrient web.

 

A seagrass meadow will also likely contain macroalgae species (Bell 1997) that have either grown as epiphytes on any of the available surfaces or having been carried into the area by water currents and snagged on the seagrass blades.  In mature seagrass meadows, the unstable leaf litter does not present many substrates on which to attach other than the seagrass leaves or the larger exposed rock fragments.  
 

 

 

https://chucksaddiction.thefishestate.net/seagrass.html

 

Application: beyond his suggestion that this is viable as a refugium as well as other suggestions he suggests at the end (with the caveat that it seems he didn't actually set up any tanks with this), it seems that trimming stuff out is necessary.  Related to that, it seems that macroalgae and microalgae (pests) are a natural part of at least the initial cycle that we'd look for in an aquarium, and that their appearance is not a cause for concern, just perhaps (based on chucks addication and the experience in this thread) that they should be cut out after a point.   

 

Finally, I've been thinking about this for a while and reread a similar thinking-thread I posted on my reef club, which included responses from someone who actually grows this.  

 

https://wamas.org/forums/topic/93227-seagrass-or-deep-reef/?tab=comments#comment-776985

 

Anyway, food for thought.  Looking forward to further updates on the tank, when you have something noteworthy to write, and again thanks for what I found a compelling tank build thread!

 

ETA: I love the idea of a tridacnid clam in the tank.  I believe derasa,squamosa, and Hippopus hippopus can be found in seagrass beds.   Maxima, crocea are generally found on reefs or flats iirc, though a quick google found some instances of them occuring in seagrass beds in Egypt.  

 

https://www.scirp.org/pdf/IJG20120500009_51785270.pdf

[billygoat]

On 10/21/2021 at 10:32 PM, KingOfAll_Tyrants said:

Application: beyond his suggestion that this is viable as a refugium as well as other suggestions he suggests at the end (with the caveat that it seems he didn't actually set up any tanks with this), it seems that trimming stuff out is necessary.  Related to that, it seems that macroalgae and microalgae (pests) are a natural part of at least the initial cycle that we'd look for in an aquarium, and that their appearance is not a cause for concern, just perhaps (based on chucks addication and the experience in this thread) that they should be cut out after a point.   

Trimming stuff out would absolutely be necessary I think, especially if maintaining a large amount of macroalgae in a small tank like this were the long-term goal. Keeping up with the nutrient needs of such fast-growing algae is a struggle! As for other algal growth... I think that if a person sets up a saltwater aquarium and doesn't see it covered in gross algal blooms for at least a little while, something is definitely wrong. In the very early stages of this tank for example, the water was pea soup for a few weeks there! This photo is from a few months ago:

 

 

Gross! But a necessary part of the process, in my opinion. 😅

 

Anyway, this system has undergone a few significant changes since I last posted:

• I moved the tank three feet to the left, so it is no longer directly in front of a huge window. Natural sunlight hitting the water was cool to observe, but in practice I found that it caused all sorts of havoc when it came to balancing lighting, temperature, etc. Once summer ended and it started to get consistently foggy in the morning here, light from the sun became very inconsistent and my animals suffered as a result. Plus since the sunlight only ever hit the tank during the AM hours, I hardly ever got to see it since I am normally at work during that time.
• Since the sun was out of the equation, I added a new light: an AI Prime. The cheap freshwater strip light I had over this tank before was a woefully inadequate source of illumination, especially once the seasons changed and the sun became less reliable. The Prime will hopefully help my seagrasses and invertebrates get back up to speed.
• Speaking of seagrasses, I also significantly reduced the macroalgal biomass in this tank. Caulerpa and friends were a cool experiment, but in hindsight they were much too aggressive  for a system like this. Hopefully the seagrasses will bounce back now that all that algae is gone. I also changed the aquascape a bit to better utilize the newly opened space.

Here are some photos of the new setup:

 

 

 

Moving forward, I am not really sure what to do with this system other than just see where it takes me. I think first I will wait awhile and see how the seagrass reacts to the new lighting situation. If it grows well I may not add anything else to the tank and just allow the plants to proliferate, but if it does not I may add a few other things to fill in the empty space.