Fertilizer Question

[Captain Hook]

Ok, I have been reading the fert sticky at the top of this section and it got me thinking. My tank is a 20 gallon with 2 wpg and I have been adding Flourish roughly every 5-7 days.

I recently had a discussion with Tom Barr in another thread regarding ferts to add. Since then I have bought Fleet for phosphate but haven't started adding it yet. I was planning on buying stump remover soon. I noticed that the fert thread said nu-salt is needed for potassium but I hadn't considered buying this.

Finally, to my question: I had a store credit recently so I decided to buy some of Hagen's NPK fertilizer. Wouldn't it be easier to add a little bit of this rather than all these separate fertilizers? Has anyone tried this NPK fert? Anyone with any experience or opinions on this please feel free to post them.

[djlen]

The reason many of us buy the separate, individual ingredients is cost. Prepared fertilizers are usually more expensive and also not particularly tailored to individual tanks.
Many of us like to be more precise in dosing certain nutrients. Adding/increasing or subtracting/reducing amounts of some of them when we feel conditions in the tank warrants it.
Your Fleets Enema will do an excellent job and last you a long time. Also, it's very inexpensive. Same for Spectracide Stump remover. KCl(nu Salt) too is one of two types of K and is more convenient than less costly. It's at your local supermarket.
If you use them in conjunction with Flourish you will be dosing a well rounded fertilization regimen, and also be able to increase them individually as needed. D
Don't know what's in the Hagen's product you refer to or the cost so I can't comment on that.

Len

[Captain Hook]

Ok here is the listing from my Plant Gro NPK fertilizer: Add 5 ml per 10 gallons to achieve 3.5 mg/L of Nitrate (NO3), 0.5 mg/L of Phosphate (PO4), and 2.5 mg/L of Potassium (K).

I didn't pay for this fertilizer. It was a credit I had from a gift return.

I am assuming mg/L is the same as ppm, is that correct? To be honest I have no idea what those numbers mean to me, in terms of how much I want to be adding. Any help from the experts?

Len I do understand more about the different fertilizers, thank you. It will definitely be easier to add specific ferts with individual ones. I am hoping to use this NPK stuff tho, just because I have it and everything is listed. If it doesn't work or gives me too much of one ingredient I will obviously stop right away.

[djlen]

What you will need depends on the quantity of plants and the lighting. But other than the K, the other two factors sound good.
2.5 mg/L(ppm), K is low. 15 - 20 would be better, but again much depends on the needs of your individual tank.
Does it say whether the N is from KNO3?
I don't like making blanket suggestions because the tanks are all very different.
If I were you, I would definitely use it and see how effective it is.
It will give you a starting point from which to adjust in the future.
I wouldn't worry too much about over-dosing with it. If you follow the directions, it looks like a relatively light dosing regimen.

Len

[Tempest]

I've used it before on a smaller tank at 1.5 watts per gallon. It seemed to work just fine but once I used it up I just started using the same chemicals as on my larger tank to save money. :)

I only dosed that tank once a week and did a 50 % water change also once a week. I upped the wattage on that tank to 2 watts per gallon and the same fert/water change routine. The only difference I really notice is the lack of a lot of algae I had on the Marsiella quadifolia(sp) and the plants pearl some now. I have DIY CO2 on this tank.

[Tempest]

Oopsie...

That's 3 watts per gallon but I have a poor reflector so probably more like 2.5 effectively.

[Captain Hook]

Thanks for the advice, I am definitely going to try this stuff out and see what happens. Len it says the sources are Potassium Nitrate and Dipotassium phosphate.

I should also add that I just noticed and read the sticky above the ferts one, regarding not dosing K+ specifically.

[djlen]

Yes, that's why I asked. If you have a light fish load, you might be just fine with the amount of K your combo fert. gives you.

Len

[plantbrain]

The Hagen stuff is fine for a well planted tank with enough light.
I see no reason why it shouldn't workm, unless it is loaded with NH4 or urea as far as sources of Nitrogen.

Other wise, it's fine and the ratio is fine also, NO3 will beht elimiting factor to gauge the other nutrients by(they will be in excess relative to NO3).

Interesting to see so many companies sell NO3/PO4 products after so many years of telling folks that excess PO4 causes algae.

Regards,
Tom Barr

[Captain Hook]

Well the fish load is fairly light right now. There are 5 zebra danios, about 5 small endler livebearers, and a pair of 1.5" killiefish.

Those ppm measurements are based on adding 5 ml per 10 gallons. Should I not fool around with anything and just add 10 ml for my 20 gallon tank? Would this be a good starting point then decide if I need to add more or less?

[djlen]

I would use it according to the directions and test your N and P to see how they hold up over the course of a week before decreasing or increasing possibly at mid-week.
I think the three most important test kits to have and use regularly until you learn your tank are pH,N and P.
Keep in mind the importance of your weekly water change.

Len

[Canuck]

Not that I can actually add anything to what has already been said, but I have used it in my tank. Works fine, but as pointed out in the long run it is much cheaper to go with the chemicals. In my tank, the N seems to be consumed at a greater rate then the P, but this may be an individual tank thing, and as long as you regularly "reset" the tank, shouldn't cause you any problems.

HTH

[Captain Hook]

Canuck thanks for the added input. I realize this NPK fert is more expensive than individual chemicals and when it runs out that is what I plan on using.

Len I think I will just try the dosage specified like you said. I am going to do a water change tonite and add Flourish and some of this stuff. Right now I have a Tetra test kit that has ph, KH, GH, NO2 (nitrite) and NH3/NH4 (ammonia). Do you think it would be worthwhile to look into N and P test kits? That seems like a lot of work to be honest. I am still trying to keep this tank low-mid level maintenance.

[promethean_sprk]

I wouldn't bother with the P, too much of it and you'll know from the algae. Peek at your plants once a day and monitor their growth, if they're growing fine just keep doing what you're doing. With a fair amount of fish, and less than 3 wpg I wouldn't expect phosphate to be too low.

A nitrate test might be good, but most test kits have 20ppm graduations, which is kind of coarse.

[Captain Hook]

I don't see much point in buying a nitrate kit if they are 20 ppm increments like you say. I added about 4 mL of Flourish and 10 mL of the NPK fertilizer after a 20% water change.

[djlen]

AP makes a pretty decent Nitrate test kit and the ppm increments are in 5ppm.
Phosphate kits are not as accurate as some of the others, but I use a Hagen PO4 kit occasionally and it helps me keep track of changes, and really helped early on when setting up and breaking in a new tank.
I guess it's up to the individual, but I wouldn't be without either of them.
I'd never want to tell that I had to much P by waiting for an algae bloom.

Len