|12-25-2012 10:13 AM
I hope you not feel i am taking over your tread CuriousAmerican but i am also going into dirt tanks (my first ) This is important to both of us.
I have done a lot of reading on the internet, also Diana Walstad's great book.
Most of the litterature regarding dirt tanks recomend a cap size of 3 mm over the soil, about 1 inch thick i tink.
Any opinions on the cap size would be appriciated, also by the tread starter i think.
|12-25-2012 04:49 AM
Keep in mind that the dirt layer will compress over time as the organics are broken down. Sand is a much better cap than gravel since it seals the dirt layer, preventing any dirt from seeping up into the water column. The methane buildup is due to anaerobic conditions from using a too fine of a sand. Having plenty of heavy rooting plants will bring oxygen into the substrate preventing the anaerobic conditions that produce methane gas. Malaysian trumpet snails also help keep the substrate aerated. With dirt tanks, the gas that is produced in the substrate when you first start out is CO2. This can be beneficial for growing your plants. If it's too much of a problem, you can use a bamboo skewer to poke some holes into the substrate to release some built up CO2 but not all at once. As for replanting, some recommend against it but I will often trim and replant a few stems every other week. A little bit of dirt may pop up but I usually vacuum whatever ends up on top of the substrate. A pipette and some extra substrate helps for touch ups. Other than that, I'd go for at least 1.5 inches of dirt capped with at least an inch of sand.
|12-25-2012 04:07 AM
My experience with dirt is that any time I remove a plant, I get some floaters. However, nutrient-wise, dirt, in any form, seems to work well. And pretty much anything on top of dirt works pretty well.
But as far as total depth is concerned, 3" is generally agreed upon as a good substrate depth. In my experience, less than 2 1/2" or so is a problem for stem plants with big root systems - they're hard to bury, and the roots will occasionally pop up out of the substrate.
|12-25-2012 03:37 AM
I use much deeper caps in my tanks. In my first dirted I used a layer of gravel to cover the bottom, potting soil to cover that, followed by an inch cap of sand and all sorts of wood chips and gunk have surfaced with zero digging or replanting.
In a later tank, gravel, dirt, gravel 2 - 3 inches of blasting sand and I have a digging banjo cat in that tanks with no problems...
If you have healthy roots/plants, methane rapidly oxidized.
Buy your sand at menards or tractor supply.. pfft on pet store sand prices.
|12-25-2012 03:08 AM
A sand cap is usually completely fine as long as it is not excessive. 3/4" should be good. An inch of both would work as well. You can also get malaysian trumpet snails to keep the substrate aerated.
|12-25-2012 02:39 AM
I know I am asking a lot of questions.
I figure a few weeks of questions here will prevent a year of bad tanks later on.
At first I considered 20gallons, then an Aqueon Evolve, until the prospect of a noisy pump scotched that. A 7.9 Fluval made sense until again, the filter was said to be lousy.
If I get a regular 10g.
Can I get away with an inch of MGOPM (UNwashed) + 1" of sand.
A 10g is only 10" high so I do not want to go deeper.
In fact I would go with 3/4" of both, if could get away with it.
I hate gravel; but I do not want methane gas buildup that comes with sand to happen.
I was thinking of using Petco WHITE SAND.
I would have a glass cover. 30 Aquaclear, and a 100W heater, for emergency heating. We have a cool room.
I was planning on using the crappy plastic covers with 2 CFL bulbs.
But is 3/4", 3/4" okay?
Or is sand totally out or the question?