Starting a new tank

[edward]

Hi All,
There is a downside in using fine grain materials for the substrate of aquatic systems. The major problem with this is that you run the risk of anaerobic pockets forming. These pockets can produce hydrogen sulfide which can kill the aquatic inhabitants of the enclosure.
Ed

 

[kai]

Hi Ed,

did this ever happen to you?

I've never experienced something like this (including less dramatic problems). Rather to the contrary I've found that coarse sand/gravel tends to be much worse for most people since leftover food can much more readily sink into the substrate and rot at leisure. If you use sand, you'll see if anything accumulates on the surface and can siphon it off (as well as think twice about the own feeding habits).

Of course, some burrowing snails (e.g. Melanoides tuberculata) are a good idea.

Best wishes,
kai

 

[edward]

Hi Kai,
Not in recent years, but when I was younger I lost fish in a planted tank that had a pretty thick sandbed. Very thin layers of sand will not develope these pockets but thicker beds may have them form.
If you ever stir a sandbed and find a black layer this shows there were anaerobic sections developing in the sand.
Another way that a deep sand bed can cause problems is by the bacteria in the anaerobic section running the nitrate cycle in reverse and producing ammonia.
If you look back in the freshwater aquarium literature that was published preseventies (and back to the thirties) these books will often recommend against the use of sand unless required for certain fish (Ex.loaches and stingrays).
If you check out the current literature on plenum systems for saltwater reef aquariums there are a number of excellant explnations of anaerobic vs. anoxic vs, aerobic nutrient cycling in live rock and sand beds.
(See publications by Jaubert or Sprung and Deelbeck and/or Goemans).
Depending upon the size of the animal I tend to use pea gravel or larger sized gravel beds and use a plain old gravel siphon to remove waste trapped in the gravel. This system has worked well for me even under very dense stocking systems (both fish and newt). (In densely populated systems I just do more water changes per week)
Having sand stirring animals will help prevent anaerobic problems but there has to be sufficent numbers of these animals and they need to be able to penetrate to all levels of the sand bed.
hope this helps,
Ed

 

[kai]

Hi Ed,

Well, I've been briefly working with facultative and obligatory anaerobic as well as microaerobic bacteria as part of my undergrad studies - really fascinating critters... ;o)
Denitrification won't give you large amounts of trouble-making products in most cases. If there is a strong temporary O2 deficiency you might get NO2- but hardly any NH3 (and the former usually because of a "completely" stuck filter).

IMHO any freshwater ecosystem can profit from anaerobic and microaerobic microhabitats and this should even hold true for reef aquaria (although I can see why this currently isn't a big deal). Hence from my POV it makes less sense to discuss wether anaerobic processes are "good" or "bad" but rather wether they are "under control" and wether their beneficial effects are adequately tapped. I've never experienced a notable problem with shallow to deep sand substrates or other anaerobic systems. Those accidents which I heard of were always the result of other faults (major human errors and long-standing neglience). E.g. if Melanoides moves out of the substrate in large numbers better head for a major cleaning instantly and do a better house-keeping job in the future - but I've witnessed this way more often with "beginners" using gravel of 2-5(-10) mm than those using plain sand. Coarse sand 1(-2) mm might be a good compromise and has to some extend the good features of both gravel and sand but I still feel that sand is better and more versatile than it's general reputation might suggest.

Best wishes,
kai

 

[edward]

Hi Kai,
As I mentioned the problems I had were with a freshwater system years ago (however my reef systems with a deep sand bed and plenum) have had no problems and only require modest amount of upkeep to keep the system happy (ammonia =0 ppm, NO2=0 ppm, NO3<5ppm). (Good to hear that your studying this process, if I have questions I can refer them to you).
With beginners the issue may be better resolved if you could list particle size by designated trade name (ex. play sand vs construction vs pea gravel ect.) as an appropriate substrate.

The time I used sand and ran into difficulties, I wsa using play sand and that may have been too fine and compacted allowing anaerobic processes to set up. (after the fish kill, I stripped the tank down and upon stirring the sand bed was able to easily smell hydrogen sulfide).

Perhaps some of my point of understanding comes from the reef aquaria side where some of the information has been made less technical for the average aquarist hence my understanding of the reverse ammonification process (although in many of these cases the particle size used was too small and the lower depths of the beds went anaerobic/with a high organic load so you are correct that human error seems to be a big part of this ).
Thanks Kai,
Ed

 

[keegan]

Question for Kai:

Thanks for your comments about sand. I like the look of it, and can see how it would be easier to clean the surface of it. Do you think it is appropriate for all/ any newts? One concern I have would be the newts ingesting it? Many care sheets suggest always having larger gravel to avoid this.

Thanks.

Keegan
PS: I'm a total beginner (no actual newts yet!), so I'm happy for any thoughts!

 

[aaron]

I'm not kai, but if the sand is fine enough, it should pass right through their system if ingested.

~aaron

 

[han]

hi!

getting an external canister started (better working) is easy when the inputtube comes straight from the bottom(glass)screen, through the screen actually: drill a hole through the bottomscreen, use a watertight connection (sink-like) for the tube (with valve to adjust the waterflow) to the canister. easy waterflow by
gravitation, better filtration, easy waterchanges.
check www.rainforest-frogs.nl for all the gear you need.

 

[matt]

but woudnt the water leak alot if you drilled a hole in the bottom of the tank?

 

[han]

i've installed this kind of wateroutput some 10 years ago in my 100 gallon tank: not a drop.
the pvc/pe "transithose" that goes through the bottomscreen comes with screw-thread at both ends.
two pvc/pe nuts and two rubber gaskets take care of a waterproof connection. a bit scary though to put the (special glass-) drill on the bottomscreen of the tank but with some practise (old glass) it appeared quite easy actually.

 

[matt]

oh ok, anyway what does this have to do with keeqan's question?

 

[han]

well, hardly anything, but "starting a new tank"
is the issue and i tried to contribute something to the canisterfiltration part of the postings.
anything wrong with that?

 

[matt]

oh well i cant be stuffed reading from the top LOL

 

[kai]

Hi Keegan,

Aaron already answered your question - I've had absolutely no/nada/zero problems with fine sand (e.g. playground stuff) and won't expect any from accidental swallowing either - sand isn't exactly unknown in many newt habitats, you know...
I'm using alluvial sand though (rounded - not freshly broken with sharp edges).

BTW, the pellets I feed to larvae of more robust species (e.g. Tylototriton) even have a little bit of sand added (to aid digestion with some fishes).

Best wishes,
kai