greg watson fert question...

[mr funktastic]

i mixed up an 800ml bottle with 6 tablespoons of phosphate which should have given me .99 ppm per ml dosed in a 20 gal. well i did my 50%water change and dose 1 ml and i checked my phosphate level and was reading well over 5 ppm(highest my test kit goes) so i checked my tap water to see if there was a spike and there was maybe .5 ppm of phosphate. so i dont understand why my mixture was soo powerful and caused such a high level of phosphate. any ideas? i just started using his ferts today since i just recieved them. so i have never made a batch before.

 

[Lonewolfblue]

Tablespoons are not exact. If you want a little more accuracy, then you need a decent scale and go by weight.

 

[Glenc]

Your mixing ratio is good, next you have to look at how acurate your test kit is. Maybe it's expired. Try shaking the crap out of it , shake the regents for a full minute and test again. I've found most hobby grade kits are not very good. If you can't spend the bucks for Lamotte, get the AP nitrate kit and the Seachem P04 kit. Only ones I have used that were close to acurate. The Seachem P04 kit is as good as Lamotte.

 

[mr funktastic]

i just bought the hagen PO4 kit. it seems to be relativly accurate. since i test my tap water and it reads maybe .5 if i am luck then i test the tank water and it goes dark blue really fast. i am sure it is semi accurate. i cant afford a lamott kit and cant seem to find the seachem kit. i dont know what to do about my mixture. i mixed up 800ml and would be a real waste to dump it and re mix it. even if table spoons is slightly off i cant see it going from 1 ppm per ml to over 5.

 

[Purrbox]

Just to make sure, did you use leveled or rounded Tablespoons? The calculator is based off of leveled Tablespoons, so using rounded ones would completely throw off the calc.

 

[IceH2O]

Just water it down until you hit 1 ppm per ml.

 

[mr funktastic]

i used a knife to completly level the measuring spoon. i did the test again after shaking the bottle for a while and it is still howing way over 5 ppm. i tested 2 of my other tanks to see the levels and they are normal. 1 ppm in my cichlid tank and .5 in my betta tank. its just the planted tank that is off the charts. i am going to pour some into a 125ml of the mix into a 500 ml bottle and then just add the rest with water and see what kind of levels i get. any suggestion on how much i should dilute it? will this mix ever go bad? i have ALOT mixed right now and cant see me using it up anytime soon. even at the current mix that i did i can dose 1 ml 800 times so thats like 2 years worth atleast.

 

[czcz]

I agree with Glen -- you can't trust your test. Put 1mL of your mix into a 5gal bucket: that should be about 4.5ppm PO4. Take half a test tube of water from that bucket and fill the with RO or tap. Thats about 2-2.5ppm PO4. Then see if you can trust the test.

You can be much much more certain your mix is ~1ppm PO4 than you can trust the test.

Also, its hard to accurately measure 1mL doses unless you have a pipette or something, and this may be your point of error. Its really better to make mixes for 5mL doses imo: this allows for more percision per dose. Also easier and saves time in the long run.

If the test and above hold up, do another 50% water change (this dilutes your last PO4 dose by half), and move forward if you want. Still do your next dose if following EI.

 

[fish_4_all]

I don't know either but I mix mine at 1 tsp/100ml water and dose 2 ml for .88ppm, 10 gallon tank, and it comes out pretty accurate by the end of the week. I also have had real problems with my test kit for anything over 1.5-2ppm. Always blue instantly and really hard to read. I would guess that it just isn't accurate over low levels.

 

[mr funktastic]

the test kit is reading accuratly. my tap water is testing around .5 same with betta tank. then my cichlid tank(which i feed more) is testing at 1 ppm. the only test that seems off is the 20 gal cause that is the only one i dosed in. i dont know an accurate way to dilute the mixture. i think i may just scrap this mixture and re do it making it 4 teaspoons per 800 ml giving me .22 ppm per ml. this way i can dose 5 ml giving me 1.1 ppm. does that sound like a safe idea?

 

[czcz]

It's a safe and good idea. Since you measured tablespoons correctly for the current mix, you could just put 200mL of the mix into a new bottle and fill the rest with tap if you wanted to -- basically the same difference. You could hold on to the rest of the 600mLs of the current mix for later, too. KH2PO4 is relatively cheap and for peace of mind I dumped lots of solutions when starting, fwiw.

Just curious: did you test PO4 before the 50% water change? Was it out of line?

 

[mr funktastic]

my po4 in my tank was always at zero. my tank just sucked up that little bit of phosphate that was in my tap water. i think my mix just went horrbly wrong. i agree it is relativly cheap but shipping is not. i ordered a pound of each so i do have lots of left over. thanks for all the tips everyone. i am going to throw my current mix into the freezer and the do a new one.

**EDIT**
ok i did a 50% waterchange and it is still reading over at least 5. i will do another one tomorrow to hopefully bring it down some more. i think i am going to stick with this mixture and play with dosing to get what i want. i will use a dropper and measure how much to dose by drops rather than ml. it will take some experimenting i am sure but will save this batch.

 

[Plantbrain]

You are putting way too much trust in the test kit.
CO2 not PO4 is the issue for most folks.
Adding 2-3 ppm a week is very common and results in awesome growth and coloration.
this is a very old observation now from many folks.

If you do a few large water changes, did not add any PO4, the tap has little, what are the odds the PO4 is really 5ppm or higher?

Now what are the odds the test kit is giving you a false reading?

20 drops on average per ml



Regards,
Tom Barr

 

[mr funktastic]

well i had large doubts in the test aswell that is why i tested 2 other tanks and the tap and then the 20 again. i think i may have used the calculator wrong or messed up and used tablespoons instead of teaspoons. ther is no way the test can test the other 2 tanks and tap water normally and then be worng on the only one i dosed in. another issue i think may have happend way that i just made th mix like 10 minutes before and shook it up and there was still powder which hadnt dissolved so i may have gotten and extream dose by some freak accident. i am doing another water change later today and if it is still registering over 5ppm i will purchase another test kit.

 

[TwoHobbies]

How could you have been that far off. 6 tablespoons into 800ml!!! If you used teaspoons you would be far less than 1 ppm.

You said you dosed 1 ml.....did you overdose by 4 or 8 capfulls. Is the 800ml bottle half empty.

For you to be reading 5ppm after two 50% water changes you had to be over 20ppm to start

Come on....That test kit must be reading wrong above 2ppm

 

[fish_4_all]

Don't let it drive you nuts, it could be something with the tank, or you could have exposed a root tab that caused your spike in PO4. Also, I don't even test PO4 anymore, I know the maximum that my tanks should have and dose EI to that levels. I can't read the colors most of the time anyway on most of the test kits, my wife has to.

 

[mr funktastic]

well the only problem is that i need to make sure that 1 dose of 1 ml is roughly 1 ppm and not 20 lol. i did dose 6 table spoons into 800 ml which should be .99 ppm per ml. i have a little measuring needle thing that reads from .1 to 3 ml dose so it is fairly accurate in dosing. i am sure i didnt overdose if i mixed it correctly. i am going to fill my extra 10 gal tank and do a half dose an test to see what kind of result i get. if i am still getting astronomical levels i will buy a new test kit and then if i am again getting high levels i will re do the mixture.

 

[mr funktastic]

ok try number 3. i did my 3rd 50% water change to get rid of the phostphates. still no go. i took a picture for comparison so u can see what i mean. there is no way the test can be that far off but there is also no way the water could have that much phosphates.

on the left is my tank water after the 3 50% water changes and on the right is the tap water. both test were dont at the same time with the same kit. how is that possible? and also keep in mine that i did the test before adding the phosphate ferts and the tank also read zero or just about.

 

[Purrbox]

Just because the kit is registering the pressence of phosphates does not mean that it is accurately representing the level of phosphates in the tank. You're best bet is to have someone test your water with another test kit (preferably a different brand) to check your results.

EDIT

Okay I just reread your post and it sounds like you did two tests on the tanks after adding phosphates and got two totally different results. If this is the case either your test kit is bad or you performed the test differently which caused the results to vary. For example barely shook one test and shook the heck out of the other.

 

[mr funktastic]

unfortunatly noone else i know has a test kits around me. i think i am just going to cave in and buy another kit. is the aquarium pharmacuticles test any good? thats the brand of all my other test and they are easier to use than the one i noght and i find more accurate. i have heard good things about the seachem kit but it is like 22 dollars for some reason. thats just unreasonable. and i have neevr even seen lamott kits in the big as near me. maybe i have to look harder. i am going to try to get to big als tonight.