First time with discus

[Fish Tank Travis]

It’s just hard to understand when everyone here and people on simply discus are telling me I’m just fine??

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Gravel and sand are different. Gravel is bigger and allows water to move through it which keeps the anaerobic bacteria from being able to create the toxic gas pockets. I still would recommend 3-4” of it though. .5-1” is plenty.

Sand is much smaller and seals off the sand underneath from the water above. This is what allows the anaerobic bacteria to creat the toxic gas pockets. You have sand over gravel which basically forms pockets within the gravel that are then sealed off from the tank water by the sand. This creates the perfect environment for the anaerobic bacteria to form toxic gas pockets.

I’m sure you’ve heard of under gravel filters, but have you ever heard of an under sand filter?

 

[jacobfata]

What if I stirred it up once a week?

 

[Coryloach]

I already answered the OP on the driftwood thread but just to add on the sand part. Gravel is a dirtier substrate prone to more anaerobic conditions due to the easy accumulation of detritus, fish food, etc..that falls in between. Anaerobic conditions are created by a combination of organic matter accumulation and low oxygen conditions. Accumulation of organic matter can lead to low oxygen conditions.

Sand, being a more compact type of substrate, actually prevents accumulation of organic matter to the lower, less oxygenated levels of the substrate.

Anaerobic decomposition, with all its negative effects is most dangerous in dirty filters used as siphons for detritus, and tank wipe outs are more likely to happen due this scenario rather than the substrate.

Think of a bare bottom tank with discus fed beef heart 3 times a day, the flying particles being picked up by the filter....a recipe for disaster. One can break their back doing water changes and still have issues....

 

[jacobfata]

So what you’re telling me is if I have a fully planted aquarium with four to five inches of sand and gravel and with weekly water changes stir the top layer of sand... my fish are still doomed? Plants oxygenate the substrate. Right?