# 30 gal new tank - plants dying during fishless cycle - fertilizer recommendations?



## thihal (Aug 10, 2018)

Hello,

I recently set up a 30 gal long tank to re-home my gold barbs from their current 20 gal tall tank. Low-tech, Mystica II inert sand substrate, 92 LED plant growth light, live plants (anubias, java fern, java moss, amazon sword). Lightly planted- about 1/3rd of floor area is covered with plants. Also added root tabs for the swords, Flourish Excel & Easy-Life ProFito. Mechanical filter (no carbon). I have an over-sized and established filter in the old tank but wanted to give the plants some time to establish themselves before transferring this filter and the fish (my gold barbs will leave the java and anubias alone, but will make minced salad out of the swords unless they are lush and green). 

Basically doing a fishless cycle on the new tank while waiting for the plants to establish. It has been 7 days now, and the amazon swords are dying without macro nutrients. The leaves have become dull and transparent. The other plants are still holding up. I've been adding fish flakes everyday under the assumption that it will decompose to produce the ammonia and the other macro nutrients needed for the cycle and for the plants. It seems this is insufficient. I also have a spare bio-wheel from my established tank that I transferred to the filter in the new tank. Water parameters were tested everyday. Nitrate is still close to zero and ammonia is less than 0.5 ppm. These were done using test strips though. I am yet to get the more reliable API master kit. 

Is there a fertilizer mix I can add to help the amazon swords? I came across a liquid NPK mix (either 5-1-1 % or 2-2-2 %) made from fish parts (ironic) used for organic farming. Is this safe for aquariums? Name: Alaska All Purpose Fish Fertilizer. I was also thinking of adding surfactant-free household ammonia if needed.

Any advice on how to proceed would be greatly appreciated.

Thanks,
Tee


----------



## mistergreen (Mar 3, 2007)

I wouldn't use it. The nitrogen is ammonium based. It's ok if you don't have any fish in there. Besides the health risk to fish, it'll probably start an algae bloom. Plus, it'll smell really bad.


----------



## RIP (Jul 12, 2018)

Since the tank is still new could you drain it and put some dirt under the sand cap?


----------



## thihal (Aug 10, 2018)

Mistergreen - thanks, I'll stay away from the Alaska Fish Fertilizer.

RIP - good idea. I was hoping to get away with having just the white sand in the long run, since all the other plants need just driftwood or rocks for support. Is dirt mandatory for amazon sword? Will macro nutrients + root tabs (micro nutrients) added to inert sand be insufficient to support this plant?

What if I get dry fertilizers (Potassium nitrate and mono sodium phosphate) to supply the required NPK?


----------



## mistergreen (Mar 3, 2007)

Yes, dry ferts is commonly used like for hydroponics.
http://nilocg.com/dry-fertilizer/individual-fertilizer/

We tend to stay away from sodium because it can build up and cause issues for plants.

Btw, you can buy root tab fertilizer, push it deep in the substrate by the sick sword plant. That'll work too.


----------



## thihal (Aug 10, 2018)

Ah, thank you for the link. This helps a lot. I did use roots tabs as well, but I didn't push them deep into the soil. The nutrients are probably just in the water column now. I'll try the roots tabs again the right way this time.


----------



## Gerald (Mar 24, 2008)

You can also push little balls of soil down around the plant roots. Saturate and freeze them so you'll have time to push them into the sand before they melt. I do this with clay-loam soil from my yard.


----------



## thihal (Aug 10, 2018)

Thank you Gerald, that's a clever idea.

After seeing a video clip by H20Plants.com, I just realized that the swords I purchased were grown emersed (based on the shape of the larger leaves in the bunch). The narrower leaves that also began to die did so due to lack of macro nutrients, but I now have the right roots tabs put in.





It looks like it is inevitable for those emersed leaves to rot before the younger shoots develop submerged and the plant bounces back. I do see a couple of tiny new shoots, so that's a good sign. Could someone confirm if I am reading this right or if I am missing something in translation? I wouldn't want to over-dose with fertilizers. Should I trim off all the transparent leaves to allow the plant to redirect all available nutrients to the new shoots?


----------



## hoppycalif (Apr 7, 2005)

thihal said:


> Thank you Gerald, that's a clever idea.
> 
> After seeing a video clip by H20Plants.com, I just realized that the swords I purchased were grown emersed (based on the shape of the larger leaves in the bunch). The narrower leaves that also began to die did so due to lack of macro nutrients, but I now have the right roots tabs put in.
> 
> ...


Leaves that have turned transparent, or are turning yellow, will not recover, so it is a good idea to trim them off. Cut them down close to the substrate.


----------



## thihal (Aug 10, 2018)

Thanks Hoppy. I've trimmed the transparent ones.


----------

