Bare bottom tanks

[Reefbum]

Reefbum unnatural, believe me, these corals are not artificial, they are alive... there's nothing unnatural about looking into a 3' reef tank and saying that it doesn't look any part of this vast and beautiful ocean.... in eyes of the beholder, lies its beauty.

Sorry bro.No offence intended.Juz like the feel of sand thats all.

[madmac]

Reefbum: No offense taken, sincerely. We all live with preconceive notions all the time... like saying the microsoft windoze(95%) is better than MacOSX (3%)... ... BTW, I was just.... have you seen the most unnatural tanks lately... Danano, Scarab, DB, Jims, just to name a few... they are so BEAUTIFUL that its real un-natural.. -- I'd love to get a chance to see them in person, MAN!

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if you guess anaerobic, then you're spot-on right, and the reasons why they are more efficient :

Anaerobic bacteria does not need O2 to survive, but without O2 you cannot have aerobic bacteria. This explains why there is plenty of aerobic bacteria on the surfaces of the LRs where there is plenty of flow, but it gets lesser as it goes deeper within the rocks. In some ways aerobic bacteria is said to be O2 limiting. BUT both these bacteria are space/habitat limited, i.e. they can't survive if there is no space!

So what has all these got to do with nutrients? and leakage? Can anyone help me here.

[madmac]

Well to answer these questions, one has to look the reasons why the leak in the first place (if at all) and if they leak, what comes out?

Remember one the above characteristics of bacteria is its ability to store food within them. The extra food is Phosphorus, P. and is stored by the anaerobic bacteria, it is made/manufactured by the aerobic. The simple way it works is like this,

--ooooooooo--- <----------decomposing food

============

==••••••••<--•==---------anoxic bacteria (sits btw the two)

==•_________•==

==•______<--•== --------- anaerobic bacteria (does not require O2)

==•_________•==

==•_________•==

==•_________•==

==••••••••••••==

============ <------- aerobic bacteria sit outside (requires 02)

Aerobic : "Hey, I have some fish poo, to work with today, I can produce x P if you want."

Anoxic : " I go ask, Anaerobic, if he can take some."

Anaerobic : "NO more pls, I'm full already and hv no more space, take it back."

Anoxic to Aerobic :"Sorry bro, he cannot anymore... you take it back..."

Aerobic : " I can't, the factory is still churning out more, how can you return it..."

That's when it leaks... if there's plenty of space, e.g. sandbeds, shallow or deep... often, one is led to believe that, when using DSBs, P is consistently low P, this is because there is still plenty of storage space for the anaerobic to store P. That's why sandbeds are no different than and any other filtration equipment, including canisters, i.e. as long as you have nitrification going on, you will have P, leaking sooner or later, and later means a big sink... and the trouble with sandbeds is that they are difficult to maintain, when say compared to a canister, which can be cleaned, and the sink is then refreshed.

Remember P as an ingredient in nutrition, so the water becomes like soup... yep increasing DOC, so you keeping upgrading your skimmer to cater for the increase nutrients, you build macro algae refugiums, etc....

Thats does not say its all bad, only that one would be striving for a eutrophic/mesotropic system, see 1st page, which will still work.

Will continue later...

[madmac]

So when we hear complaints like, Help, my NO3(nitrates) has gone up, something is obviously wrong, not just with systems with sandbeds, canisters or even BB tanks... it means the system is starting to fail, the sinks are full, nutrients P are leaking out...

This can happen to BB tanks, when the LR has gotten too dirty or algae has grown to choke out the O2 the aerobic bacteria needs, they die off, giving their space to the anoxic bacteria to move upwards, the anaerobic bacteria also has more space now, but the whole de-nitrification process fails without the aerobic bacteria....

Sorry to take so long to answer your question Patrick... since we're on BBRK here, the idea was spelled out in page 1, :-

• yes, a strong skimmer, tuned to wet, will certainly help.

• A good turbulant flow is very necessary, to keep the detritus away, if that can't be achieve,

• try you best to take out the detritus before it gets a chance to decompose, by siphoning

The pic below shows, the detritus from my tank collecting in the front centre in 12 hrs... it gets siphoned off to a container, when it settles, I pour back the 3/4 of the water back to the tank.

[madmac]

correction

... sorry I made an error in the 2nd paragraph, last line...it should read as

...but the whole nitrification process fails without the aerobic bacteria.

De-nitrification is the process where nitrate is converted back to nitrogen gas. It is a process that only take place in the absence of O2.... it is often wrongly thought of that anaerobic bacteria does this as there are no O2 where they are. They dont'.

This denitrification process requires a specially built filter and a steady supply of organic carbon source... yes it can be read as sugar... sometimes they can work naturally in a tank, when O2 supply is low, esp at night... but this process stops in the day time.

[madmac]

Thot I update this thread to include pics on rock cooking... This set was started on 20 March... I did the first water change yesterday... on observatioin, the water stank and is yellow... there are many decaying animals, worms esp, some half out of the rocks... the rocks are slimy to touch... and yes they smell.

I'm thinking that the dead algae cause an ammonium spike, which killed off all the critters, which cause even more ammonium to be released. The whole idea of the rock cooking is to prepare the rocks so that they're bacteria driven instead of algae driven. Detritus will constantly be release until a stage when no more will be produce... thats when the rocks are ready for use. They're kept in the dark... another 7 to 8 weeks to go.

The pic shows what was after the first water change... It looks like it deserves another set of cleaning and water... some coraline algae is starting to die off, the 2nd from the top-left rock was just put in for comparison, 1 week later. Pic taken with flash.

[madmac]

Two mths later, tis pic show what it looks like. The rocks are very rough to feel, even sharp at some points. I thrown the water out, for the pic. I'm putting the rocks in the canister filter... to make use them.

[madmac]

Tis pic shows the close up of some of the rocks. They look very porous and useful now.

Other than that, theres not much to update tank wise. some coraline algae is starting on the bottom glass surface, 5mm ø