Is it possible to overdose? - Page 2 - Fertilizing

Red_Rose · 07-22-2008, 11:41 AM

Quote:

Originally Posted by hooha

do you do any water changes or just top offs?

If you do water changes 1-2x/month dosing 10ppm (i.e. 1/8 tsp) of potassium sulfate every 2 weeks shouldn't be a problem. If you don't then 1/16th would be a safer number and increase in 4 weeks if you still see signs of defiency......at least that's how I would approach it

I only top off the tank but I soon will be doing a water change so I can remove some of the mulm that has built up on the gravel.

I think I'll just stick with trying 1/16 for now like you suggested. If I don't see improvements, I'll up the dosage.

I don't want to take the chance of adding to much to the tank.

I do have a question about potassium nitrate. A friend told me that when he doses his 20 gal, 1/4 gives him 10ppm of nitrate so he suggested that I try 1/8 so I would end up with 10ppm. When I had first dosed the tank, I was nervous about adding too much so I had added about 1/16(or slightly more) to my 10 and it gave me 10ppm. Whenever I use one of the online fertilizer calculators, it says that it should've given me 5ppm and not 10. Could the fertilizer that I'm using be more concentrated?

hooha · 07-22-2008, 09:26 PM

you may be adding 5ppm nitrate, but there is still nitrate in your tank - possibly changing your reading from the tank. The other possible cause is the nitrate kit itself being off.....

That's a little more plausible than the nitrate being more concentrated (especially if you're using a 'dry' fert like straight potassium nitrate)

Red_Rose · 07-23-2008, 05:28 PM

First off, I just want to thank you for sticking with me through all of this! I never thought I'd have to add ferts to my tanks until my plants started showing signs of a deficiency.

I'll take a sample of the water to a LFS to see if the nitrate results are the same. I've had the test kit(Freshwater Master Test kit from API) for over a year so it's very possible that it's not accurate anymore. Once I get it tested, I'll know for sure if my test kit is off but until then, I'll dose the potassium sulfate every two weeks.

Just out of curiosity, what exactly is a "lockup"? Is that what you mentioned before about excess K utilizing calcium and magnesium(for example) or is it something different?

hooha · 07-23-2008, 09:04 PM

no problem, just make sure you update us on the progress in the next few weeks

as a 'lockup' i'm not sure what that refers to - can you point to a source? It may be the process where excess of one nutrient inhibits the use of another.....

Red_Rose · 07-24-2008, 06:55 AM

Will do.

I had added my first dose of the potassium sulfate on the 15th of this month so should I wait until next week to add my next dose or should I add it either today or tomorrow and then redose every two weeks from there? I'm also going to get my water tested today so I'll post the nitrate results later on.

If you look at the section that tells about calcium deficiencies at the bottom of the page on this link, you'll see where it says 'lockup'. Perhaps something like this only happens in extreme cases.

hooha · 07-24-2008, 09:59 PM

I would go ahead and dose next week for a 2 week interval.

Yes, from what I gather, 'lockup' refers to the iniability to utilize nutrients as I mentioned above. I think the levels have to be relatively high to get those types of problems in your tank.

Red_Rose · 07-25-2008, 12:10 PM

Great! I'll do this for a couple of months to see how things go so I'll give you an update then.

hooha · 07-25-2008, 10:33 PM

Great, good luck! If you have any other questions and I miss this thread feel free to pm me