# Gravel as Substrate for Live Plants



## jschlosser

Not saying I won't be adding something more conventional, but if I were to stick with just gravel as my substrate, what kind of plants could I grow? I think I can scrounge about and find mid and background plants, but are there foreground/groundcover possibilities?


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## Gfish

Anything you can grow in a specific planted aquarium substrate can be grown in standard aquarium gravel. Fine gravels with a diameter of 2-5mm will serve you best, especially if you want some form of carpet plant like Glosso or HC. Using substrate fertiliser tablets is a big advantage when using plain gravel.

Exactly what plants you choose for your carpet/foreground will depend on what lighting you have & if you are using co2 or not. What substrate you are using will make little difference.


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## jschlosser

That would be great as I sit here with my box of laterite trying to figure out how to get it under the gravel! Trying to avoid the CO2 if I can; am running 2x54 6700 T5 HO lights over 15" deep 55 gals.


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## Gfish

The substrate will be fine but with that amount of light I don't think you will have any choice but to add co2 & fertilisers. 2x54w T5HO is pretty much equivalent to 216w of standard T8. Without the co2 & fertilisers you will probably get a huge algae problem.

The laterite will only provide iron so I wouldn't be too worried about using it. If you really want to add something to the substrate you could add a layer of Eco-Complete over the top of the gravel. Eco will supply iron in the long term & other minerals short term. It has a high cation exchance capacity so it will absorb any fertiliser you add so that it is available when the plants need it. Add a little at a time so that you con't cloud the tank right up. Over time it will mostly settle itself under the gravel.


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## jschlosser

It's a lot more light than was in there before, to be sure. I was almost talked into twice that much. I am aware that it may lead to algae issues, so whatever I need to do, I need to get to it.


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## NursePlaty

*It would be very hard to grow foreground plants with plain gravel. Fish feces and left over food is not adequate. Plants such as HC (Dwarf Baby Tears) or HM (Baby Tears) require bright light and nutrients from the floor and due to the small leaves they will need CO2. HC needs more CO2 than HM. Your tank has 2watts per gallon over 15" so I dont think you need to worry about CO2 AS MUCH but it will help. If you have 3+ wpg you might want to consider it. My HM are doing nicely now with 2.45wpg after I reduced it from 3.45 wpg over a 12" tank. 

When I first started with plants, I could not grow HM with just plain gravel. I retried them with Mineralized soil and a layer of gravel on top and they grew nicely. Of course with my 3.45 lighting without CO2.. I also had a thousand species of algae growing all over the place just as Gfish mentioned "huge algae problem". I then lowered watts and added 3 bottles of DIY CO2 linked in series and introduced FlourishExcel. The old algae is still there, but I dont see any new ones coming up.

If you just use plain gravel. I would suggest plants that use nutrients from the water column that dont depend too much on the gravel such as java fern species, anubias species, water sprite etc. I think other plants such as Lilys, Cryptocorynes, Limnophilias etc will take the majority of its nutrients from the floor (mostly the plants that have a moderate root system).*


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## Gfish

With respect NursePlaty, I've grown HC, Glosso, Crypto Parva, Pygmy Chain Sword & Dwarf Hairgrass in tanks using plain gravel & gotten good coverage with no problem. The trick with these plants is to use substrate fertiliser tablets that are rich in Iron. API substrate tabs work well. Most people who don't have success with those plants in a plain gravel substrate either don't use substrate tablets (or the wrong ones) or the gravel diameter is too large. With anything under 1/8" (4mm) gravel & the right substrate tablets, they will grow just fine.

The WPG rule does not apply to T5HO lights. That rule was based around either T8 or T12 flourescents, (there's debate which one). Either way they have similar intensity output per watt. Seeing as T5HO flourescents have approx twice the intensity per watt, the WPG rule is useless with them. If you do want to try to apply it, you first have to double the wattage number & then divide that number by the gallons of the tank. So 2 x 54w T5HO is 108w, 2 x 108w (double the output) is 216w. 216 divided by 55 is 3.927. So this tank is much closer to 4wpg than 2wpg. At anything over 2wpg co2 is mandatory no matter.

Also worth noting that the OP is lookig for foreground carpeting plants & none of the ones you have suggested NursePlaty, are foreground or carpeting plants.


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## NursePlaty

*
 my bad. 

I did not use root tablets. So maybe that is why my HM never lived. I did not know T5HO lights doubled in intensity. They looked just as bright as the others to me. But I just now read up about it and its multiplied by 1.6 before applying WPG.

I read his post fast and saw him talking about looking for midground and background plants. Along with him talking about if its possible to grow foreground plants. So I just talked about everything in general. I didnt suggest him foreground/carpet plants because I didnt believe carpets can grow on plain gravel. If I thought they could, I wouldve named a few. *


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## Gfish

No problem. I've been guilty of reading stuff too fast & making mistakes or not having enough coffee in the morning before posting on forums & getting things all wrong.

The substrate tabs make a big difference to how well carpet plants do. There are always low light carpet options to like Water Clover (Marsilea Hirsuta) or Java Moss grown on craft mesh anchored to the bottom with a few large pebbles. Another good carpet plant is Downoi/Little Star (Pogostemon Helferi). It's really a medium light plant but when grown under low light conditions the leaves stand up vertically giving a broad grassy appearance. it's a really good carpet plant when kept under med-high light.


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## jschlosser

I am reading the instructions for using the laterite and what I am coming up with is removing all but an inch of the gravel, adding the well-rinsed laterite and thoroughly mixing it with the gravel before returning the rest of the gravel I have removed. Sound right? I am also looking into a CO2 system. I have an idea for a DIY set up that does the auto cutoff when the lights cut off without making my husband any madder than he is about how much I have spent lately  , that is, releasing the CO2 into a chamber where I will have another air pump and have that pump run it through an airstone and have the air pump on the same timer as the lights. I have all the makings for that here in the house except the pop bottle but I think I can get my hands on one or use something else (says she, eyeing unused sports bottle in cup holder of barely used eliptical machine. . . ). Will let you know how that goes.


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## Gfish

If the laterite is in pellet form then mixing it with an inch or so of gravel in the bottom & then covering it up will work fine but IMO it's best to completely strip & empty a tank to put laterite in. Laterite goes on the very bottom, then 1/2" of sand, then 2" or so of gravel on top of that. The sand makes sure that the laterite cannot leech into the water column.

With the co2, it's not worth the hassle of trying to divert the co2 at night. It's much easier just to have an air pump set on a timer with an air stone in the tank. Have the pump switch on when the lights are off. The extra surface disturbance created by the pump at night will help dissipate the extra co2 the plants are producing & help prevent the ph crashing overnight.


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## jschlosser

Wasn't so bad adding it, actually. I removed half the gravel, added the well-rinsed laterite from a measuring cup - cloud was gone in under 10 minutes - then moved the gravel from the other side of the tank on top of that. Second side goes in after supper tonight. Now, I still want to add the Eco-Complete if there is an advantage to it that cannot be addressed using liquid plant foods or root tabs. If I do, though, I have to order it online. Neither Petsmart or Petco carry it and my lfs went out of business in January.

Sitting here watching my bubbler finally do its thing. Can't find single airline connectors other than the plastic ones that come apart around here - which is what happened to the one in the top of the "brewery" overnight. I did get lucky and find a brass hose nipple that I was able to use that was even better. 

http://www.stainlesssteel-fittings....steel_hose_fittings_hose_connectors_stems.jpg


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## jschlosser

OK. I can see the bubbles in the bubbler but they are not coming out on the tank end. Right now, I just have the air line in the water, nothing obstructing it but it is full of water up to the surface of the water. I went ahead and caulked every single connection to rule out leakage through those and it still isn't going through. What could be happening?


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## Gfish

Either the yeast mixture isn't reacting or most likely you have a leak somewhere. Could be anything from the lid of the generator not sealing properly to a pinhole in the airline somewhere. You can either use a process of elimination & rule out one thing at a time or you can submerge the entire generator complete with airline in a tub/bucket of water & find where the leak is that way.


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