Planning for a dirt + coarse sand (or gravel) planted tank for the first time.

[Vexus]

Hello, so I'm attempting my first planted tank and I'd like to do a combination of dirt with a coarse silica sand or maybe a bonsai lava grit cap over it. The tank I'm using is a 36-gal Topfin bowfront 30.7 in L x 15.7 in W x 22.2 in H (77.9 x 39.8 x 56.3 cm). My question is how much of each substrate should I use? I know the 1 Lb to 1 gal rule, as well as adding an extra inch for planted tanks but because I'm mixing 2 substrates, I was hoping to get a more precise ratio. 

Any advice from someone who has done something similar or just has more knowledge in general about this would be greatly appreciated.

[Kittkat1981]

While I havnt done a dirted tank yet I am getting ready to do a 75 gal mini paludarium, complete with dirt capped bottom. If you don't use specific aquarium dirt, you can use miracle grow soil. Just make sure it is organic and also sift it first to get wood peices out.  You don't need much either. Cap it with the substrate of your choice and go.  Look up the walstad method aquariums.  

[Beardedbillygoat1975]

I would avoid the silica sand, it will be diatom city and you will be very aggravated. The same for playground sand. The lava grit or crushed lava rock would be much friendlier. A simple inert aquarium gravel is another option for cap. If you have a hardware store close you could consider black diamond medium blasting sand which is an inert coal slag that is aquarium safe and is attractive to look at and cheap. pool filter sand my concern there is that it has a tendency to compact and would be harder for your plants to make their way through to the nutrient layer. I would buy extra substrate, one bag more than you are thinking, you can always use it for your next setup. I always under dirt rather than over dirt, it's so nutrient dense that especially with starting out you want less algae and blooms of things then more. 

[HH Morant]

I have a Bonsai Jack lava rock substrate (see photo below).  I am setting up a new aquarium and I will be trying coarse coal slag blasting media (see picture with quarter). 

I like the looks of the course coal slag better than the medium, which looks more like sand.

The particles in the coarse coal slag are still much smaller than the Bonsai Jack lava rock.

[Vexus]

Thank you for the advice, that coal slag definitely looks nice, originally, I was avoiding a black or white cap option so fish waste wouldn't be so prominent, but I normally do weekly water changes (with the planted I imagine it'll be every other week at most if at all) so I could just make it a day to do a light skim over the rocks to get any excessive buildup that doesn't sink below. Making a natural looking tank is also very appealing to me (which is why I was considering the silica), so if I go with a natural look, would sandstone have the same issue with diatom? I know sandstone contains silica I just wanna double check to make sure if it's the same thing or juts looks similar due to a shared trait. And if so, would the plants be able to counteract the diatom like other algae?

Also, as far as the bonsai lava gravel, I've been having trouble finding a supplier, everywhere I look they either don't have it, it's too big for what I'm looking for or it's not very cost effective ($14 for 2 lbs. is not ideal). As it stands the slag looks like the best option at $10 for a 50 lb bag at the tractor supply co.

OH! I forgot to mention I'm also thinking of doing a dry start method for some carpeting plants to incase that also matters on what cap I use. I don't think it would though....

And in case it matters, my cleanup crew was going to involve corys, shrimp (ideally a self-sustaining cherry family with an amano or 2 added) and a few hillstream loaches. I'm on the fence about adding snails.

Edited December 7, 2021 by Vexus

[Intuos]

If you are mixing substrates I would recommend that you get yourself some media bags with plastic zips to help keep them separate. As to the amount of "dirt" you would need a lot will depend on what you use so not really sure there is a rule as such. 

[Vexus]

At this point I really think I'll go with the medium grade coal slag. It looks good, its cost effective and my wife likes it lol. As far as the dirt I'll use, it's a toss-up between a miracle grow organic dirt or just plain nothing special about it dirt and add some root tabs to it.

[Streetwise]

I use 1-1.5 inches of organic topsoil with the shortest gravel cap that I can get away with for planting and flow. I have had issues with sand choking out the soil and putting roots in anaerobic conditions. I really recommend getting the Diana Walstad book, even if you just skim it and use it as a reference.

I don’t mind some non-floating wood bits, because shrimp love them. 

[Vexus]

First off, I want to thank that all of you for your advice and suggestions. They were great and gave me some really good ideas. But after doing a little more research and talking it over with my wife, seeing as this is our first truly planted tank and first-time housing neocaridina shrimp (or any shrimp really), we have decided to pay the extra amount and go with CaribSea Eco-Complete red substrate (although the bag says eco-planted). I know completely left field on that decision lol. I'm surprised we came to that decision in the end myself. I may come back to a sand/dirt tank again in the future after i get a better feal of what I'm doing but i think this is the safest path for me as a first attempt. Again, I want to thank you guys for taking the time to make suggestions and give advice and seeing as this was my first thread on the forum, I'm glad to know if I ever need a little help I can ask and you all and others will be there to help.

Now I'm off on my next adventure of finding a good co2 regulator that isn't too expensive but a high quality lol.

[PineSong]

Another natural-looking substrate that compacts less than sand but is finer than traditional gravel is Carib Sea Peace River. It hides fish waste well, looks natural and my plants are thriving. It's not too sharp so I'd trust it with cory barbels.

[Beardedbillygoat1975]

@Vexusits always an issue of time or money or both. In this case I think it’s a great choice. I’ve used eco-complete many times and never been unhappy with it. Do follow @Streetwiserecommendation to grab Diana Walstad’s book it’s really great. Father Fish did a great video on it as well. Best of luck and look forward to seeing what you come up with. Oh and have fun!