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Discussion Starter #1
So I just purchased a phosphate test kit the other day and just used it tonight for the first time. I was informed on here that a phosphate test kit and a nitrate test kit are good tools to tell the parameters of the fertilizing process and how much your tank is consuming. My water parameters are:

PH: 6.6
Nitrate: 2.5
Nitrite: 0
Ammonia: 0
Phosphates: 10+

Tank setup includes:
90 gallons
3xT5HO 6700K and 1x T5HO Actinic
Pressurized C02 at 1-2 BPS

Fertilizers:
3/4 tsp KNO3 3x/week
1/4 tsp KH2P04 3x/week
1/4 tsp Plantex CSM+B 3x/week

I have no algae bloom going on and can't really see any algae problems going on in the tank besides little black dots that form on the leaves of my Amazon Swords but only when the leaves are dying which I remove when I do my weekly 25% water change. Is there any concerns over having this high of phosphates in the water? Do I increase my KN03 supply by another 1/4 tsp 3x/week to ensure that there is enough in the water column?

Just looking for any and all advice as the phosphate test kit is new to me. Thanks!
 

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I used discus and neutral regulator buffers in my water on suggestions from one of the local fish gurus. I did not know that they were phosphate based but upon looking it up the reasoning was that it helps maintain buffer capacity. So far in my tank, I have not had any algae blooms either. I don't know how much my phosphate is per se but I would imagine its higher than normal. Just my 2 cents into the phosphate deal :)
 

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i would just say you may not need to dose phosphorous for awhile until it drops down a bit, but no it shouldn't an issue. As tom would say, he doses a bunch all the time as per ei and it's never caused algae.
+1 :)
 

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I would kit the nitrate up to 5 - 10 ppm, and just stop dosing phosphates until it comes down below 3 ppm or so.
 

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I have the same high phosphates. Could API pH 6.5 be to blame?
 

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I wouldn't worry so much. Check your water source and food also if you want to find out.

Plants fix their own P with the help of ectoenzymes and such at root level. So as stated above, you may be getting enough with those and can skip dosing.

There is no problem with high phosphate IME.
 

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If you really have 10+ ppm of phosphate in the water, each water change drops that by about 25%, assuming your tap water is not the source for the phosphate. After 8 water changes, 8 weeks, you would be back down to 1 ppm of phosphate, with no consumption of phosphate by the plants and no dosing of phosphates.

If the plants are growing as fast as they should be, given the very high light you have, they should be quickly using up the phosphates you are dosing. But, you don't have nearly enough CO2 to allow them to grow that fast. Something isn't fitting right here. Exactly what light fixture do you have, and how far above the top of the tank is it?
 

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The only way I could see you not co2 limiting is because you are limiting nitrates, and/or the plant species you are keeping have very low co2 requirements. Regardless, it seems you may be walking a tightrope or just plain lucky with the balance you have going and no algae.
 

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Phosphate is generally harmless to fish. Too much may lead to an algae outbreak.

If you are trying to grow shrimp on the other hand, this is what I've found out through tragic experience:

CRS and Babaulti Green - Highly sensitive
Neos and Tigers - Adults don't seem to mind it. Tiger babies don't seem to like it.
 

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Phosphate is generally harmless to fish. Too much may lead to an algae outbreak.

If you are trying to grow shrimp on the other hand, this is what I've found out through tragic experience:

CRS and Babaulti Green - Highly sensitive
Neos and Tigers - Adults don't seem to mind it. Tiger babies don't seem to like it.
Hi, sorry to hijack.

How sensitive? I mean ppm.

Thanks'
 

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Depends.....too much of any one chemical can cause your plant having difficulties to use another. I generally keep my level around 5 to 10. Since your kit only goes up to 10, you can't really know how much phosphate you have. I would avoid using any additives containing phosphate. Test your tap water for the phosphate level too. I use Phoslock on my treated water to remove any phosphate as much as possible, down to 1 or 2 ppm. Then, I would add additional phosphate from EI (about 3ppm).
 

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Discussion Starter #15
I would just say you may not need to dose phosphorous for awhile until it drops down a bit, but no it shouldn't an issue. As Tom would say, he doses a bunch all the time as per EI and it's never caused algae.
HAHA yea. I didn't dose any today and a water change comes tomorrow.

I would kit the nitrate up to 5 - 10 ppm, and just stop dosing phosphates until it comes down below 3 ppm or so.
I put in an extra 1/4 tsp in today so we'll see how it goes.

I wouldn't worry so much. Check your water source and food also if you want to find out.

Plants fix their own P with the help of ectoenzymes and such at root level. So as stated above, you may be getting enough with those and can skip dosing.

There is no problem with high phosphate IME.
I have to check my tap water yet. I forgot to test it yesterday so tonight or tomorrow I'll get it tested.

Did you calibrate the kit with a known solution? That's your first step.
I did not know I needed to calibrate it...maybe that's my problem?

If you really have 10+ ppm of phosphate in the water, each water change drops that by about 25%, assuming your tap water is not the source for the phosphate. After 8 water changes, 8 weeks, you would be back down to 1 ppm of phosphate, with no consumption of phosphate by the plants and no dosing of phosphates.

If the plants are growing as fast as they should be, given the very high light you have, they should be quickly using up the phosphates you are dosing. But, you don't have nearly enough CO2 to allow them to grow that fast. Something isn't fitting right here. Exactly what light fixture do you have, and how far above the top of the tank is it?
I'll keep an eye on what happens after water changes to see what happens with my phosphate levels. It could also be like jcgd mentioned about calibrating the kit. I'm going to look into it.

I just recently upped my lighting from using only two of my lights to using all 4. The reason I'm only running 1-2 bps is because my PH dropped like crazy to around 6.2 so I cut it back a bit. This was also when I was only using 2 bulbs though as well. The light isn't the greatest quality. It's an Odysea fixture so the reflectors aren't anything as the nicer fixtures. It came with the tank when I bought it. That's the reason I have it. The light is just sitting on the tank so it's only about 1"-1.5" off the top. Since upping the light my growth has increased and the pearling has gone crazy at night.

The only way I could see you not co2 limiting is because you are limiting nitrates, and/or the plant species you are keeping have very low co2 requirements. Regardless, it seems you may be walking a tightrope or just plain lucky with the balance you have going and no algae.
So if I up the nitrates I should up the C02? Is that what you are saying? Again as mentioned earlier, I am afraid that my PH is going to drop like crazy again.

Depends.....too much of any one chemical can cause your plant having difficulties to use another. I generally keep my level around 5 to 10. Since your kit only goes up to 10, you can't really know how much phosphate you have. I would avoid using any additives containing phosphate. Test your tap water for the phosphate level too. I use Phoslock on my treated water to remove any phosphate as much as possible, down to 1 or 2 ppm. Then, I would add additional phosphate from EI (about 3ppm).
I am ceasing all usage of phosphates for now until I get this whole test kit figured out just in case. We shall see how it goes.
 

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HAHA yea. I didn't dose any today and a water change comes tomorrow.



I put in an extra 1/4 tsp in today so we'll see how it goes.



I have to check my tap water yet. I forgot to test it yesterday so tonight or tomorrow I'll get it tested.



I did not know I needed to calibrate it...maybe that's my problem?



I'll keep an eye on what happens after water changes to see what happens with my phosphate levels. It could also be like jcgd mentioned about calibrating the kit. I'm going to look into it.

I just recently upped my lighting from using only two of my lights to using all 4. The reason I'm only running 1-2 bps is because my PH dropped like crazy to around 6.2 so I cut it back a bit. This was also when I was only using 2 bulbs though as well. The light isn't the greatest quality. It's an Odysea fixture so the reflectors aren't anything as the nicer fixtures. It came with the tank when I bought it. That's the reason I have it. The light is just sitting on the tank so it's only about 1"-1.5" off the top. Since upping the light my growth has increased and the pearling has gone crazy at night.



So if I up the nitrates I should up the C02? Is that what you are saying? Again as mentioned earlier, I am afraid that my PH is going to drop like crazy again.



I am ceasing all usage of phosphates for now until I get this whole test kit figured out just in case. We shall see how it goes.

I find the API phosphate kit is pretty accurate. Accurate enough. When my phosphate level is below 5 ppm, I will begin to see green spot algae.
 

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HAHA yea. I didn't dose any today and a water change comes tomorrow.

You need to know what you are starting with (tap), what's in the tank water, and what you are adding to know what you need to do, if anything.

I put in an extra 1/4 tsp in today so we'll see how it goes.

I have to check my tap water yet. I forgot to test it yesterday so tonight or tomorrow I'll get it tested.

Let us know what the results are.

I did not know I needed to calibrate it...maybe that's my problem?

Not necessarily, you just calibrate it against a know solution. If you may a 10ppm solution and test it with your kit, the kit may be correct, or off a bit. If your kit says 20ppm when you know your solution is 10ppm (or very close to it) you can re-mark your kit to reflect the real results.

I'll keep an eye on what happens after water changes to see what happens with my phosphate levels. It could also be like jcgd mentioned about calibrating the kit. I'm going to look into it.

I just recently upped my lighting from using only two of my lights to using all 4. The reason I'm only running 1-2 bps is because my PH dropped like crazy to around 6.2 so I cut it back a bit. This was also when I was only using 2 bulbs though as well. The light isn't the greatest quality. It's an Odysea fixture so the reflectors aren't anything as the nicer fixtures. It came with the tank when I bought it. That's the reason I have it. The light is just sitting on the tank so it's only about 1"-1.5" off the top. Since upping the light my growth has increased and the pearling has gone crazy at night.

A few questions:
1. Why did you up your lighting?
2. Ph drop is all relative. Injecting co2 and going from ph 6.8 to 6.2 is not drastic. From 7.8 it is getting pretty big, but can still be possible and fine. What ph is the tank in the morning before lights on or co2 addition?
3. What the tank having any issues before the changes?


So if I up the nitrates I should up the C02? Is that what you are saying? Again as mentioned earlier, I am afraid that my PH is going to drop like crazy again.

Not exactly, I'm just saying with your current conditions, high light, low co2 (assumed), and high phosphates it is unlikely, in my opinion, that the plant growth is being limited by only light. If you really have 10ppm phosphates, which is high, but likely not an issue it is non limiting. You appear to have pretty low nitrates, and low co2. So one, or both, or both plus other factors are limiting the plant growth. Maybe all is good if it's working, but it would be good to know what is really going on in the tank. For example, of you add nitrates and change nothing else, your plants may stunt. Or not. But if they do, you probably stopped limiting nitrates and now you would be limiting co2. So you can see how many factors play a role on plant growth, the speed and the quality. Sometimes, if it ain't broke you don't fix it.

In most cases, the easiest way is EI dosing, achieving the desired levels by dosing in conjunction with the tap water parameters, Nice high co2 and keeping the light low enough that it limits growth.

I am ceasing all usage of phosphates for now until I get this whole test kit figured out just in case. We shall see how it goes.
See red text.
 

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+1 jgcd

I would definitely keep the light at 2 bulbs. You want light to be your limiting factor, not co2 or ferts. Upping the light will most definitely increase the need for more co2 the most as well as ferts, and if your co2 limited you're asking for an algea farm. Te ph drop isn't serious at all as te water isn't actually at that ph, it just reads that way due to the co2, if you let the co2 off gas it'll be normal again. I also hope this is a fish tank and not a shrimp tank or again, you're also asking for shrimp problems :/. I'd stick with everything you've done and just ya, keep it at 2 bulbs until you know what you can up. At most, I'd use all 4 for a 1-2 hour "burst" in the middle of te photoperiod.
 

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Discussion Starter #19
Ok so here's what I have. Sorry for the non quotation but I will do my best to answer the questions. Tested my tap water for phosphates and it was between 0 and .25 ppm. Tested my tank water again and it turned blue before I could even begin shaking it.

I upped my lighting because my LFS recommended upping the light so I figured I would give it a shot.

I tested my PH and it was still 6.6. When I put water in a cup and ran an air pump in it for about 20-30 minutes it read around 7.6. So is my PH actually 7.6 or is it 6.6?

The tank was having water quality issues. This is what got me talking with my LFS about my tank parameters and somehow the lighting was mentioned to bump up. I've now started pre-treating water 10 gallons at a time for about an hour or so with an air pump and Seachem Prime.

As of right now I'm using the EI dosing method. I have been now for almost a year that I've had the tank and haven't really had too many problems until recently. I'm going to cut the lighting back to two bulbs. What about what HolyAngel said about doing a 2 hour burst during the afternoon? I thought that you only wanted to focus on changing one thing at a time. That was why I was curious if I should just up the nitrates. Are you suggesting to up the nitrates and the C02? I appreciate all the help with everything!
 

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Hi, sorry to hijack.

How sensitive? I mean ppm.

Thanks'
I've read CRS can't tolerate >5 PPM.

For greens I'm not sure. My phosphate was above the 10ppm the test kit shows, and my Neos and Tigers were breeding, while my Green's were dying off.

Lowered phosphate through water changes, and the Greens that were left stopped being stressed.
 
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