Phosphate Levels

[ASpec]

Quick question regarding phosphate levels. I just recently purchased the phosphate test to complete my line of test kits.

My tank has been established for 8 weeks now. I started adding plants about 4 weeks ago and they are doing quite well. I had a green hair alage problem around week 4 (couple days before I started adding plants) and it's since gotten much better.

Here are my levels, please tell me if you see something out of line. I know my nitrate needs to be up to rid the alage completley, hence I have ordered some KNO3 from Greg Watson.

58 Gallon, 192 watts of PC 10K and 67K light (12 hour cycle), Pressurized CO2 injection (on a SMS 122 controller), Eheim 2126 Thermo Filter, Coralife 9 watt UV (24/7), 100% eco complete substrate

Amm: 0
Nitrite: 0
Nitrate: 0 (will add KNO3 soon to move this up to 5-10ppm)
GH: 3
KH: 7
Phosphate: 2
PH 6.9
CO2: 25 to 30
Temp: 78-80F

No fish, just plants at the moment. Are all my test results in line? I am wondering if the Phosphate is high or low. I started dosing Tropica Master Grow last week and I do a 20% water change (tap water) every week.

Thanks!

 

[LAGlocker]

Well most people i think will say a good ratio of nitrate to phosphate is about a 1:20 ratio i belive it is. It may be a 1:10 ratio but you get the point. For every 1 ppm of phosphate you want 10 to 20 ppm of nitrate in the tank. at least that is what I do, and dont have any algae problems. also what other fertilizers are you dosing? any besides the tropica? I havent ever used that myself, I does micros in a kent suppliment, and macros seperatly, so that I know what ratio of each I am putting in the tank, and can dose according to what the plants need.

 

[czcz]

Your test results make sense. 2ppm PO4 is a good if arguably high number if you dosed N and K too. With your light and CO2, suggest you dose NO3 to at least 10ppm to start, simply to avoid NO3 bottoming out again. PO4 uptake may then increase, so keep an eye on it. Suggest you add KH2PO4 to your gregwatson.com order if you can since I think you will be most successful dosing all macros and micros on a schedule, but others may disagree. Good luck.

 

[ASpec]

Thanks for the replies. I've already submitted my order to Greg Watson so I'll pick up the KH2PO4 later.

I am only doing Tropica Master Grow right now. I dose this on Monday and do my water change on Saturday/Sunday. I don't really want to dose daily, or every other day so I am attempting to use Tropica (weekly dosage).

When I start adding KN03 (at get my Nirates up - maybe 10-15 ppm) will my PO4 fall or go up? Thanks

 

[BlazerFRS]

Should fall as the plants use it up; they can't use much of one without the other.

 

[rich311k]

Yes test the Phosphate and keep it at a 10 to 1 ratio with the nitrates.

 

[malkore]

Well most people i think will say a good ratio of nitrate to phosphate is about a 1:20 ratio i belive it is. It may be a 1:10 ratio but you get the point. For every 1 ppm of phosphate you want 10 to 20 ppm of nitrate in the tank.

Ok, I'm just being picky here. LAGlocker does explain it right, but his first sentence has it reversed.

So it's 20 nitrate to 1 phosphate.

--

Ok, now that we're straight...I like a 1:10 ratio, and I like to run 1.5ppm phosphate to 15ppm nitrate. Its balanced, and as long as I keep up my phosphate dosing (my cichlids are nitrate factories) I have good growth in most plants.

 

[workfortheman]

<<not trying to hijack this thread>> but what are some signs of phosphate deficiency? discoloration of plants? is there a particularly good indicator of phosphate deficiency?

 

[BlazerFRS]

Deficiency: Phosphorus

Effects: Old growth first

Symptoms:
Stunted growth.
Sometimes leaves become darker green
Also symptoms can be similar to nitrogen deficiency

http://www.csd.net/~cgadd/aqua/art_plant_nutrient.htm


Nothing too distinctive or obvious, really.

 

[malkore]

One indicator is increased green spot algae on the glass walls of your tank. Doesn't always appear, but if you have to strip the walls every day, you're phosphates are low.