[tokpaler]

I found two actually, both local brands:

Ramgo's Complete Fertilizer

N 14%
P 14%
K 14%

And the other one ( forgot the brand though)

Total Nitrogen 19%
Urea Nitrogen 13.5%
Nitrate Nitrogen 3.5%
Ammionical Nitrogen 2%
P2O5 19%
K2O 19%
MgO 0.033%
Fe 0.025% (chelated)
Zu 0.013% (chelated)
Mn 0.013% (chelated)
Zn 0.005% (chelated)
Maximum Bulret 0.4%

Both are terrestrial based ferts. The instruction for the first one is to bury it 3" away from the roots and the other one is to be applied with a foliar spray.

I'm not sure whether I can use this for my planted tank (48x24x22, laterite substrate mixed with river sand, medium to high light with no CO2 yet) and how much of it I can use.

Help? =b

 

[Diana]

I know you are in a difficult location to get ferts, so if that is the best you can do, try it.
If there is any way of setting up a smaller test tank with just a couple of fish, that would be safer than risking your main tank.

If you can bury the slow release ferts deep in the substrate, I think that would be the best way to go. The ammoniacal source of N in the second fert is a bit worrying. If you can test that, use a VERY low dose.

 

[DarkCobra]

This is not an element:

Zu 0.013% (chelated)

You probably meant Cu (copper), which is a necessary part of any complete fertilizer.

But it also has a lower toxic threshold in aquatic environments. And, in addition to what Diana said, this is other common problem with terrestrial fertilizers - they usually include too much copper.

Compare your fert:

Fe 0.025%
Cu 0.013%

To CSM+B, which is commonly used in aquariums:

Fe 7.0%
Cu 0.1%

Ignore the difference in quantity. Since CSM+B isn't a "complete" fertilizer with macros like N/P/K, it's more concentrated, and you use less. Look instead at the massive difference in *ratio*.

Again, as Diana said, you can use it sparingly and probably get away with it; though I wouldn't risk it if you keep any invertebrates you're attached to, as they will be more strongly affected by copper toxicity.

 

[Darkblade48]

I am with Diana as well, the second fertilizer's source of ammonical nitrogen is worrying.

The same could be said for the first; you will need to see where the nitrogen is coming from. If it is coming from urea, you are best off not using it.

While urea can be used in the aquarium to dose nitrogen (and a few people have experimented with it), I would advise against it for any aquarium that has livestock.

 

[tokpaler]

Thanks for all the replies! I wrote a lengthy reply a while ago, only to find out that I had to log in again due to a crappy connection and now it's gone =b

I forgot to mention that the tank doesn't have occupants yet, so I figured I'd give it a shot albeit a small shot.

I did a little bit of research and found out that both ferts are from the same company, so it's a safe bet that both N are Urea Nitrogen based. I did a bit of asking around and found out that most hardware and gardening stores don't carry KNO3, it being a component for dynamite and some fishermen actually use it =\ sad really...

Also, I forgot to mention that the tanks have no occupants yet.

I dissolved a teaspon of the complete ferts in the tank (the instructions says two tablespoons with 20ml water) and mixed it in. I came back to check on it several hours later and observed that the ludwigia repens was pearling, it's the first time I noticed it doing that ever since I planted it a couple of weeks ago. I'm not going to risk it when I put the fishes in the tank though, not until I find out what my parameters are exactly (no test kits yet, would've bought one earlier but the LFS was closed since it's a holiday).

I'm going to try the slow release ferts next after I do a 75% water change and I'll report back with the results.

Darkcobra, I did mean Copper. Thanks for pointing it out. The manufacturers listed it as Zu so I assumed the symbol was correct. =b

 

[Diana]

With no livestock in the tank then the conditions are a lot more like growing land plants, container plants or house plants.
While I cannot say, "Anything goes", I will say that you have a lot more leeway in what you use.

When you are raising land plants in the soil or in containers the excess fertilizers can leave the root zone. Build up can still be a problem under certain conditions.
Make sure you are dosing small amounts and monitoring what is going on, then doing water changes to dilute any excess.

I am not sure what to do when you are ready to add livestock, though. Some of the minerals in these fertilizers can get bound up in the substrate, then released later, becoming a source of toxins in the tank.