Confused about soil use in shrimp tank.

[Peable]

Hi sifu(s) of AQ,
I'm curious of soil (no specific brand)use in shrimp tank. Their main purpose is to buffer PH. Am i right to assume it only buffer down instead of up? If one only has Neo shrimp in tank it's perfect to use tap water reconditioned for WC or top up. If Neo lovers using RO for WC and top up wouldn't that stress the shrimps more, as RO PH is acidic and when it goes into the tank, the soil buffers it more lower. Is this the reason some hobbyist tend to lost their shrimp for unknown reason? Lets just put those PH up product aside in this matter.
Sorry for my blunt question.
I find that even i don't buffer anything just using tap water 7neutral for my Neo tank with lots of aeration, i find that the PH will drop somehow. Can someone explain is it possible? aeration bringing down PH? No soil, normal substrate without function only house benificial bac.

[Urban Aquaria]

Active soil substrates are commonly used to buffer pH (usually to slightly acidic conditions for plants or shrimps), but most shrimp soils also release some beneficial minerals and the soil also provides extra surface area for beneficial to colonize too.

If the source water has even lower pH than what the soil is supposed to buffer to, the soil doesn't buffer it back up.

When using R/O water, you are supposed to re-mineralize it to get the target trace elements, minerals, TDS and pH before water changes... it's not used directly to fill up a tank at its pure distilled form, as fishes and shrimps still need the essential trace elements and minerals in their water.

Topping up with R/O water is different as it's only in small amounts, the evaporated tank water has still left behind the elements and minerals, so it's okay to top it up with pure R/O water to maintain the TDS levels.

Co2 lowers pH, hence aeration actually tends to increases pH, this is because it promotes gas exchange and reduces Co2 levels.

Since you have a bare bottom tank and not using any active buffers, the pH dropping in your tank is mainly due to the effects and by-products of beneficial bacteria consuming and breaking down organic waste in the nitrogen cycle. The more organic waste being processed, the greater the cycle's effect is on lowering the water pH.

In your case most likely the pH decrease from the active nitrogen cycle has a greater effect than the pH increase from the aeration, hence overall pH still gradually lowers over time.

[Peable]

Oh wow never thought of that. Thank you Urban Aquaria the info you provided leads to some other question. Is it okay for shrimp in this enviroment in a long run? I mean with aeration 24/7. I don't wanna off it as the weather is humid, they are under a small fan and i read somewhere it's better to provide aeration in hot weather but never thought the effect would be that much. I did 30% wc every other week. My PH 7 neutral from tab but overnight after wc it dropped to PH6. Am i right to assume it is because of the humid weather as it increases organic waste?

[Urban Aquaria]

Oh wow never thought of that. Thank you Urban Aquaria the info you provided leads to some other question. Is it okay for shrimp in this enviroment in a long run? I mean with aeration 24/7. I don't wanna off it as the weather is humid, they are under a small fan and i read somewhere it's better to provide aeration in hot weather but never thought the effect would be that much. I did 30% wc every other week. My PH 7 neutral from tab but overnight after wc it dropped to PH6. Am i right to assume it is because of the humid weather as it increases organic waste?

If your tank is focused more on shrimps (and less on plants), then having constant aeration is good as it increases surface agitation and improves the dissolved oxygen content in the water. More oxygen in the water is always better for shrimps, especially when the tank temperature is higher, as warmer water holds less oxygen.

On the other-hand, for planted tank owners, they prefer low surface agitation/aeration in order to retain Co2 in the water for the plant growth. In this case, the high density of plants are the ones which increase the dissolved oxygen content in the water through their active photosynthesis activity. So there are different ways to create oxygen in the water.

Hot weather and the resulting higher tank water temperatures accelerate the metabolism of both shrimps and beneficial bacteria, so they tend to eat more, grow faster and also produce more waste, so it does contribute to increased rate of production and processing of organic waste.

[Peable]

My tank is just low tech with moss, water sprite. Alright then i understood now thank you so much.