Anaerobic substrate

[FishDad]

I recently rearranged some of my rocks in my 125g and disturbed some of the lower layers of sand which is between 1 and 2 inches in thickness. These layers were clearly darkened and some spot even released the classic air bubbles that signifies anaerobic bacteria.

Question #1: Internet research was some what vague. How serious is this?

Question #2: With recent troubles with sand and impellers and now this, I am considering completely removing the sand as a substrate all together. I'm kicking my self for not useing a coarser sand or even a gravel. What do you think?

 

[exhumed07]

i have never had an issue with anything like that with my sand. my sand is thick in spots but my cichlids are constantly shifting it. about once a month i have to spread it back out cause they move all the sand to one side of the tank. and the sand in the filters issue is kinda the nature of the beast. i cut my intake tubes pretty high to prevent most sand from getting into my filters but it's not a cure all and about every other year i have to buy new impellars cause they shafts get ground down and littereally break in some cases. as for the anarobic bacteria i wouldn't think it should be to big of a problem. the thing about anarobic bacteria is they don't use any oxygen and what bubbles may be released into the water column go through and burst at the top so quickly that any toxic gas that may be in the bubble will not absorb into the water. i'm used to seeing bubbles in my dirted tank due to either bacteria or just the natural process of decy from the organic mater in the soil. but to me honestly i don't think there is much to worry about with that bacteria. and i am not claiming to be an expert in this as i have never researched any of this before but just personal opinions based on the limited info that i do have.

 

[exhumed07]

here u can see what I'm talking about

 

[exhumed07]

Also I'm unsure as to y my phone posts pics sideways when I don't take it sideways lol

 

[FishDad]

Yeah you got 5 inches of substrate. Well it just made me nervous to see those signs. I'm still thinking of redoing the substrate all together. Its just such a hassle.

 

[Rotaripsnoc]

There are brands of pebble that are small, and are smooth, your Cichlids should be able to move it pretty well with little fear of cutting their mouths, or becoming am obstruction if they swallow, or vent through their gills. I'm looking for it now it's been a while since I've used it. Even in my salty tanks I'd use it, my rays never had issues with it, and shrimp dug tunnels in it easily.

As far as the gasses, if they were going to be harmful they would already be in your tank and affecting your fish. Gasses in substrate will always try to escape, most of the time in micro bubbles that are either removed by carbon, or released in your filter. The area I would be cautious with, is where your decorations trap it, large bubbles won't harm your tank but it can be absorbed by wood \ ceramics \ porous resins, and can turn an unsealed decoration into a toxic area of the tank.

Also with anaerobic organisms being disturbed, you might want to monitor your water stats more. Anytime I'd move live rock in my salt tank, I'd have ammonia spikes, from the bacteria dieing when they come in contact with the o2 saturated water.

Just my 2 cents on the topic.

 

[FishDad]

Good info, thanks Rot. I've got an ammo card so its always being monitored. All of my decor is rock. Granite and Flagstone... I think. Shouldn't trap much right?

 

[exhumed07]

flagstone is like slate right? if so i wouldn't think it would hold much and i never thought about the o2 killing the bacteria. that is a good point.

and only the one side of the tank is 5 inches deep. they like to move it to that side for some reason lol. and the sand can be a hassle i agree. i got 2 tanks with sand 2 with gravel. my 55 with my cichlids cause well i know they love sand but they stir it up alot and it gets into the filters. my 30 gallon with the brichardi is a pretty calm tank. not alot of movement so there is no issue there. my 20 gallon where i now house my sunfish is gravel but he likes to dig things up and moves fast so sand would be a bad idea with that. and my other 55 i used gravle for my plants. i've heard some bad things about sand in dirted tanks.

 

[FishDad]

I may be wrong when I say flagstone. Its the color of sandstone but not nearly as brittle. The granite is awsome. For some reason down on the lake there is TONS of busted up pieces of wine colored granite. Perfect for the aquarium.

 

[Rotaripsnoc]

The granite should be fine, it's used in kitchen counters because of it's low porosity. The other, I'm not sure if there is a significant difference in weight for stones nearly the same size I would test it.

You can perform a basic test by doing this: How to Calculate Stone Porosity | eHow.com

You could also compare it to granite to get an idea of if it is good \ bad.

However if you've not had any mysterious spikes or illnesses you're probably fine.

 

[FishDad]

Good info again. I've been using this stone for over a year now, in various tanks, it should be fine.