# What to put under inert substrate?



## murph (14 May 2010)

I had intended to use an inert 2-3mm black gravel substrate with some playsand in the foreground buy I'm worried that I'm setting myself up for failure by not giving the plants any help from the substrate?  I'm hoping that my EI dosing and co2 injection can take up the slack but is there anything, cheap, that I could use as a base layer?


----------



## ceg4048 (14 May 2010)

How about Garden Direct's Osmocote - Controlled Release Plant Food 50 million times cheaper than ADA Oki Nowa or whatever...

Cheers,


----------



## murph (14 May 2010)

Cheers mate! Homebase it is then!


Will any similar fertaliser do the job?


----------



## ceg4048 (14 May 2010)

I imagine than any slow release fertilizer will do the job. Just be very careful though because you can get into trouble very easily if the ammonia content of the product is too high. Homebase should sell Osmocote I would've thought. We know this product but we're less familiar with other types.

Cheers,


----------



## murph (14 May 2010)

None in homebase    so I'll try else where!


----------



## ceg4048 (14 May 2010)

murph,
          Just click on the blue link and it takes you directly to Garden Direct. This is one of (if not THE) cheapest places for ferts, unless of course you have issues with buying stuff on-line.

Cheers,


----------



## murph (14 May 2010)

Cheers Clive will do. How much do you reckon? 2-3kg?


----------



## ceg4048 (14 May 2010)

You don't need a lot mate. Get the smallest, unless you want to also fertilize your shrubbery and flower beds outside as well.

Cheers,


----------



## Nick16 (14 May 2010)

yeah i got 1kg of the stuff and it has lasted me ages. i go overboard on the stuff when i put it in but it has done my 240L and my 4x2x2 and im only about 1/2 way though! 

B&Q stock it i believe, but i got mine from ebay


----------



## ceg4048 (15 May 2010)

By the way, this needs to go at the very bottom of the substrate. I believe the suggested amount is on the order of 1-2 teaspoons per square foot, so just scatter it evenly at the base of the tank., then put the substrate on top. 
This product does contain Ammonium Nitrate, so if you keep it at the bottom and avoid disturbing the substrate too much, you will avoid leeching of ammonium up into the water column. This shouldn't be any worse than what Aquasoil does, which is notorious for leeching NH4+.

Osmocote is a gel encapsulated NPK product. The NPK slowly leeches out of the gel based on the temperature. Warmer temperatures cause higher rates of leeching. It is primarily for terrestrial plants but even when submersed, it does not become waterlogged. This is good to use with any clay substrate in particular, but with any substrate generally.

If you have access to peat, you would do well to lay a very thin layer at the bottom as well. The peat provides carbohydrates to the rising population of bacteria. ADA Aquasoil, which sells for a kings ransom (as do other designer substrates), is basically clay baked with NPK and peat. It's the cats meow of substrates, but the effects can be easily simulated with the combination described above for loads less money, especially if you are dosing the water column regularly. I recall JamesC used a similar configuration in his Akadama journal, which is a sticky at the top of this section. Check it out.  

Cheers,


----------



## dw1305 (17 May 2010)

Hi all,


> Osmocote is a gel encapsulated NPK product. The NPK slowly leeches out of the gel based on the temperature. Warmer temperatures cause higher rates of leeching. It is primarily for terrestrial plants but even when submersed, it does not become waterlogged. This is good to use with any clay substrate in particular, but with any substrate generally.
> If you have access to peat, you would do well to lay a very thin layer at the bottom as well.



I like the "osmocote", peat (or leaf mould) and clay (calcined or otherwise), topped with sand approach. The nutrient addition is easy to calculate, and you can choose the colour of sand(s) you like.

cheers Darrel


----------



## Kosh42-EFG (17 May 2010)

Surely trying to put sand over something like Akadama is only going to end up in a mess?


----------



## dw1305 (18 May 2010)

Hi all,  





> Surely trying to put sand over something like Akadama is only going to end up in a mess?


 I think the answer to this is "yes it will", because the small, dense sand grains will inevitably fall through the larger, lighter calcined clay. If you don't do any "gardening" it takes longer (Trying shaking muesli in a jar, you can quickly separate it into a top layer of dried fruit and nuts (eat) and a bottom layer of rolled oats (give to the kids) ). The tanks I set up with a 75:25 sand:gravel substrate now have an entirely gravel top layer, despite the fact the substrate has never been syphoned (presumably the MTS and fish cause enough substrate disturbance). I only use about 10%  1:1 clay:leaf mould (& osmocote), with pure sand on top,  so it is largely a silica sand media. In the tanks where I used "Seramis" this has migrated upwards.

cheers Darrel


----------



## Kosh42-EFG (18 May 2010)

My tank started with topsoil topped by gravel. Now it is mainly gravel topped with topsoil 

My next tank is going to be one substrate only (except for a scattering of Osmocote at the very bottom)...


----------

