Why are reef tank rocks devoid of life?

[CoralB]

Everything one can see , including all biology questions, comes down to a chemistry question, and all chemistry questions boil down to physics questions, and all physics questions ultimately are math questions.

That’s just the way of the world!

Unless your a leprechaun LOL !!
Always looking for me pot of gold .

 

[stevieduk]

I think having rocks like this is cool. I bought some KP rocks, and most of the life is gone after 2 years. Do you have rocks that kept their life? If so, please share your secrets! lol

I still have real living rock I bought in the 70s, life has spread to all the tufa rock I put in with it

 

[areefer01]

It’s very difficult to claim a product will help a linckia starfish because not even scientists have figured out their diet.

One could always not buy the Linckia starfish.

 

[Miami Reef]

One could always not buy the Linckia starfish.

Very true. I can’t argue with that.

But I am trying my best. I did what most don’t usually do.

 

[areefer01]

Very true. I can’t argue with that.

But I am trying my best. I did what most don’t usually do.

I should apologize as I was not passing judgement only replying what crossed my mind as I was reading through this. That and I remembered I snapped a couple videos this past December while diving in Fiji. I came across them a couple times both on shallow reefs and sandy areas covered with turtle grass and macro algae. Including gold mantle clams of various sizes.

One of those animals that we have always been taught to not purchase hoping one day that the collectors learn there is no money thereby leaving them in the wild. Again not directed at you just ranting that we have been at this since the 90's yet they are still in trade.

Edit: on topic, again I apologize. My opinion is rather simple as to why reef rocks do not look like that in the wild. We don't feed properly and hobbyist are afraid of algae.

 

[Miami Reef]

It could be an interesting experiment to culture stuff on tiles or whatnot and see what the link is like to crawl on. I’d try it if I had one.

I could even make controls of tiles soaked in plain saltwater and place it next to the bacteria-coated ones in my tank.

This sounds like such a fun experiment. I can’t wait to set up the tanks when I get home.

Can I use sharpies on the tiles and later place them in my display tank? Is that reef-safe?

 

[Randy Holmes-Farley]

I could even make controls of tiles soaked in plain saltwater and place it next to the bacteria-coated ones in my tank.

This sounds like such a fun experiment. I can’t wait to set up the tanks when I get home.

Can I use sharpies on the tiles and later place them in my display tank? Is that reef-safe?

I expect a normal black sharpie is fine. I’ve used them to label things that I put into the water.

 

[JonoH]

I have an abundance of sponges growing around the tank, but mostly in the sump where i keep a heap of live rock.

 

[Faurek]

Yup. When I got my liverock for my 5G, I had one more piece that wouldn't fit so I put it in my 20G.

The life between the two is vastly different. The 5G is growing and showing more life.
The 20G rock has slowly receded, very few sponges left and most are in shade.

Really gives a perspective on what different conditions will provide.

Tell more about both tanks, I have tried with different tanks as well, but the only tank where it didn't die as fast was set up with sand from the same shore and constant water changes from the same place, then eventually died except coralline.

 

[Dragen Fiend]

Tell more about both tanks, I have tried with different tanks as well, but the only tank where it didn't die as fast was set up with sand from the same shore and constant water changes from the same place, then eventually died except coralline.

The biggest difference is age, fish and no sandbed.

The 20 gallon long was meant for a friends fish who had cancer. He didn't want to part with them so I took them though I already had a pair so I set another tank up. This tank was strictly for the fish and coral fragging/coral QT.

Its running a seachem HOB, glowrium light bar and no sandbed. I through in cured rock and tons of marine bio balls.

The parameters are exactly the same. as the deskmate, may fluctuate a bit more than the deskmate. Though I'm sure the light and flow are vary different.

The 20 gallon was already established 3 months in before I placed the extra rock in. Within a couple of days I can already see die off vs the rock in my deskmate. The coralline did not take. Up to this day, only a few small orange sponges are on it and maybe a couple of feather dusters. All the macro algae and coralline is gone.

The deskmate was live sand plus live rock. Sandbed about 1.5 inches. A couple of cured marine bio balls from the 20 gallon was tossed in the AIO chamber as well. Its easier to maintain such a small tank. I personally believes Pico/nano tanks are much more easier to grow if you already understand the hobby.

 

[Miami Reef]

I expect a normal black sharpie is fine. I’ve used them to label things that I put into the water.

Do you know if bacteria (nitrifying) have a preference on what media they prefer?

There are ceramic, aragonite, glass, and even cement materials to choose from.

The torch coral had a calcium carbonate base, so maybe I should just start with that?

 

[Randy Holmes-Farley]

Do you know if bacteria (nitrifying) have a preference on what media they prefer?

There are ceramic, aragonite, glass, and even cement materials to choose from.

The torch coral had a calcium carbonate base, so maybe I should just start with that?

Sorry, no. Some organisms grow faster on more hydrophobic surfaces, like coralline on plastic, but I don’t know if that applies to what you want to grow, and a linkia maybe getting little bites of plastic may also be undesirable.

 

[Hans-Werner]

Ok, different approach, and it was already touched in this thread: Why does life rock and why do mangrove look like they do? Why are they full of life?

There is a lot of high carbon/low nutrient organic detritus floating around, remains of macroalgae, microalgae, seagrass and mangrove leaves. These are the basis for growth of microbes and the food webs. It is not vinegar floating around.

There are investigations on the nutrient and protein concentrations of the food of detritus feeding fish like Ctenochaetus. These investigations show that the protein concentrations of the detritus is higher than the protein concentrations of the algae and leaves the detritus originates from. The degradation process and the growth of fungi, protists and bacteria increases the protein concentration and the general nutritional value of detritus in marine environments. (Link1, Link2, Link3, Link4, Link5)

Replicate this with vinegar.

 

[sixty_reefer]

Randy shows what I can only describe as infinite patience explaining things in this forum. He will provide detailed explanations, citations, and links to people who ask questions even if that information is clearly posted at the top of the forum in sticky threads or has been asked 3 times that week.

You reply to him by telling him to use google scholar if he wants to learn something.

Unbelievable.

Please don’t take sound bites and make it sound like I’m being rude!
If you going to quote me, I would appreciate that you add the full post.

 

[rishma]

Biofloc is not a waste water treatment system is a method used in aquaculture that converts nutrients into organisms that can feed fish and crustacean creating higher yields with less pellet feeding.

Thinking about it, I may not bother with it, I’ve not used the name of the brand of the product till this thread and only reveal it as I thought it may help Miami with his star problems. Since then not even a thank you! I don’t really need to prove anything to anyone really.
It’s working for what I need and it’s creating floc in the same way as it’s used in aquaculture.

In resume carbohydrates are more nutrient rich than vinegar that it is a clean form of carbon. You should be able to pull a few articles on google scholar supporting this if it’s something you would like to expand your knowledge.

Please don’t take sound bites and make it sound like I’m being rude!
If you going to quote me, I would appreciate that you add the full post.

That is a weak excuse. if you felt that the last sentence of your post was rude when you saw it quoted, there are appropriate ways to respond and remedy that.

Attempting to deflect and take issue with how you were quoted is not one of them.

I don’t know why I bothered.

 

[sixty_reefer]

That is a weak excuse. if you felt that the last sentence of your post was rude when you saw it quoted, there are appropriate ways to respond and remedy that.

Attempting to deflect and take issue with how you were quoted is not one of them.

I don’t know why I bothered.

I’m not bothered as the person who ask for ideas and “brainstorming” just hide itself behind Randy (as usual), instead of making their own questions they relying on his approval for something that Randy don’t seem to understand. It’s hard to contribute wend folks can’t think for themselves imo
This is the reason I’ve answered as I did, I don’t mind discussing with folks if they are truly interested.
If you wish to help perhaps you could tell us what’s the difference between acetic acid and complex carbohydrates and the different effects in microbiology and nutrients. With complex carbohydrates being key here.

 

[Miami Reef]

I’m not bothered as the person who ask for ideas and “brainstorming” just hide itself behind Randy (as usual), instead of making their own questions they relying on his approval for something that Randy don’t seem to understand. It’s hard to contribute wend folks can’t think for themselves imo

Really? You asked me to hear your brainstorming. I said let me hear it.

You gave your opinion. My knowledge was limited in that subject, so I waited for someone with more science, chemistry, and biology experience to give their opinion.

What more do you want from me? I’m doing the responsible thing by not pretending I know something when I don’t.

 

[rishma]

Collaboration requires respect, not condescension.

@Miami Reef please accept the best contribution I can make to this thread. You might find it improves enjoyment of this discussion. I’m giving it a try.

 

[Randy Holmes-Farley]

There is a lot of high carbon/low nutrient organic detritus floating around, remains of macroalgae, microalgae, seagrass and mangrove leaves. These are the basis for growth of microbes and the food webs. It is not vinegar floating around.

There’s more acetate consumed in the ocean than any other organic. It is at the core of many biological processes including the breakdown of carbohydrates.

I’m not making any representation about its effects vs any other organic, but it should not be dismissed out of hand.

 

[ISpeakForTheSeas]

I don't have time to make a proper response right now (I'll comment again when I do), but with regards to keeping Linckias - they're thought to consume biofilm in nature (and this theory has some lab-based support as well), but we're not sure what in the wild biofilm is important for them nutritionally, and we're not sure what the specific biofilms they eat are composed of.

I've been looking into ex-situ biofilm recreation, and while the tiles for growing them are a good idea, it likely won't work because there are an insanely large number of variables involved in biofilm growth and development (what species of bacteria, diatoms, fungi, etc. are available to be in the biofilm, flow, light, other species around them, water chemistry, the properties (chemical and physical) of the substrates available for them to grow on (porosity is a big factor), etc.).

Essentially, because we don't know exactly what kind of biofilm they eat, we'd essentially be left guessing at how to produce the proper biofilm from scratch (not an easy task, though I have been looking into it a bit to try and play around with it in the future), and the possibilities are basically endless. If you already have the star, then I'd encourage experimenting with trying to find a preferred feed for it, but I would have some tempered expectations on the odds of success.

Anyway, for our current best hobbyist knowledge on keeping them:

Personally, I currently recommend against trying to keep a tropical, true starfish (Asteroid) species, particularly biofilm-feeding species, except for Aquilonastra stars.

That said, if you're really determined to try keeping them anyway, I'd strongly suggest setting up an Aquilonastra farm, a cryptic refugium to farm sponges, and possibly a colonial tunicate farm as well (all of these should be separate from the Linckia's tank so they can't get to the farm and ruin the "crop") - the Linckias feed on these (they presumably emulate biofilms to some degree), and the most successful Linckia keeping I've seen have always involved at least one of these aspects (typically the Aquilonastra stars).

With Aquilonastra stars alone, I've seen people keep them 2-3 years; with the cryptic refugium sponges involved too, the longest I've heard is ~4 years. Still not good by my calculations, but arguably acceptable if they really only live a decade.

For those who are truly determined to keep true starfish against my recommendation, here are some signs to watch for to help track starfish health:

Some ways to potentially gauge the health of the starfish that may be useful:
1 - Visual: is anything visually wrong with the specimen? (From what I know of starfish, these cues are generally pretty obvious if they're there at all - if the starfish is disintegrating, there's something wrong).
2 - Weight: is the specimen putting on or maintaining weight (generally healthy), or is it losing weight (under most circumstances, this would be unhealthy)?
3 - Size/Length: if it's not already full size, is the specimen growing? Is it shrinking (either from weight loss, disease, limb loss, etc.)?
4 - Reproduction: is the specimen engaging in reproductive behaviors/activities (i.e. courting, nesting, spawning, etc.)? (I recognize this one is not as common of an indicator in captive starfish at this point, but there are a few instances of starfish attempting to spawn in captivity).
5 - Longevity: is the specimen relatively close to meeting, actually meeting, or exceeding their expected wild lifespan (or at least surviving for a few years - healthy), or is the specimen dead/dying prior to doing so (unhealthy)?
6 - Speed: how quickly can the specimen right itself when it's flipped over?
7 - Level of activity: how much is the specimen moving around? (Generally speaking, low activity indicates poor health; moderate activity indicates good health; and high activity indicates good health but probable stress - it could be searching for food, oxygen, etc., but it's probably not in terrible health when moving a lot).
8 - Grip strength: does the specimen have a strong hold/grip with its tube feet? (A strong grip indicates good health, a weak grip indicates poor health).
9 - Willingness to eat: is the specimen eating? (Seems obvious, but can be really hard to tell with some stars - some stars leave little trails called feeding scars through the things they're eating; sometimes you can see their everted stomachs; other times, like if they're feeding on biofilm, you may not be able to tell at all - them crawling onto visible food is a good sign they're willing to eat, but - as mentioned above - the food may or may not meet their nutritional needs).

And a final note on starfish keeping:

One important thing to keep in mind with foods for these guys - just because they eat it, doesn't mean it's meeting their nutritional needs; it might be, but it might not be. With how long it seems to take these guys to starve, unless you're monitoring their health closely, you might not notice if it's not meeting their needs until it's too late.