Alfagrog as a substrate or other clay substrate that does not decrease PH

[neoyyf]

I am looking for a substrate that does not lower PH for a planted tank. Now to my understanding the best substrates for a planted tank are the ones that lower PH but i keep snails so i dont want that to happen as it will dissolve their shells.

I am currently looking at clay type substrates as they can increase ph, make the water harder or are inert, any of those is fine for me. Also it is imperative that the substrate does not cloud the water when moved about as i am new to aquascaping and will move stuff about constantly. Also has to be easily obtainable in the UK. I came across Alfagrog by accident and found out it can be used as a tank substrate.

Now the manufacturers do not claim it to be a good substrate for plants but they advertise as a good filter media as it is highly porous. They do a small 5mm grain size which is sold as being suitable as a substrate.

Since it is a fired clay, i am assuming it has a high CEC (cation exchange capacity). It does contain a whole array of minerals but because it is fired to a high temperature, i am unsure if the plant roots can absorb any of it. Apparently the minerals do not leach into the water and does not alter the water column PH.

So has anyone used it as a plant substrate?

 

[Byron]

The substrate is the most important factor in an aquarium. It has to be suitable to form a bed for many different species of bacteria, far more than live in the filter. Live plants rooted in the substrate also factor in. And of course, fish species, as some need sand for instance.

You do not want to be using filter media as substrate. The best substrate material is inert sand or fine gravel. Sand is needed for many catfish, and smaller cichlids which also feed from the substrate. Fine gravel, up to pea gravel, can be effective in a Central American or Indian/Asian stream tank for some fish like livebearers and barbs respectively. Plants will root well in sand to fine gravel.

When you get into so-called plant or enriched substrates, you encounter various issues. Most plants do not benefit from any of these, unless you are intending a high-tech aquatic garden sort of planted tank where the plants are the focus with few or often no fish. Plants in fish-centered tanks will be fine without such substrates.

Concerning the effect on water parameters by substrates: the initial GH and KH and pH of thee source water factor in, and the substrate composition. A calcareous substrate will tend to dissolve mineral into the water, raising GH, KH and pH. The natural tendency in any aquarium with fish is for the pH to lower due to the normal breakdown of organics which produces CO2 which creates carbonic acid, lowering the pH. The extent to which this will occur depends primarily on the buffering capability from the initial GH/KH/pH.

Byron.