# Need advice on balancing my tank to remove GSA & Staghorn Algae!



## meyscapes (19 Jan 2022)

Hello!

I have a Dennerle 35 Scapers tank that has been running since September 2021 and it’s my first high tech setup with a Chihiros WRGB2 and pressurised Co2 system. I previously had the light set up at 50-60% intensity for 6 hours a day, but a couple of months ago I increased this to 8 hours as the tank was more established and the plants were doing well, so I thought this would improve their growth even more. This caused GSA to start appearing on the rocks at quite a fast rate and so I recently reduced the lighting intensity down to 40-50%, still for 8 hours a day. 

Before this change the plants were doing great and growing really well, but in the last couple of weeks I’ve noticed a big slow down in their growth rate. On top of this the GSA is still there and I’m now also starting to get staghorn algae on the plants!

Today I calculated my Co2 levels using PH and KH and I discovered that my Co2 level is actually higher than it should be. I’ve always had a drop checker in the tank which reads as light green and so I assumed this was good, but when I did the KH and PH tests, my KH read as 4.5-5 and my PH was 6.6, resulting in a Co2 level of around 30-37ppm. 

Almost all of my plants are classed as “Medium” by the Tropica website and so I was wondering if I should either:

1. Reduce the Co2 amount first as they naturally require less and this could also match my newer lower lighting intensity? 

And/Or 

2:  Just go back to 50-60% lighting intensity for 6 hours a day as from what I remember this seemed to have the best plant growth. 

Then again, I’m not sure if the initial fast plant growth was because the setup was newer and so there were maybe more ferts available for the plants in the soil, as it is the ADA Amazonia soil. The only other ferts I’ve been adding to the tank is a daily dose of 2hr aquarist apt zero.

Either way, with all of the variables between lighting, Co2 and ferts I’m a bit overwhelmed on how best to solve this or where even to start 😅

 Any help or advice would be very much appreciated, thank you!


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## MichaelJ (19 Jan 2022)

Hi @meyscapes  Welcome to UKAPS  

I am not a CO2 expert, but your algae issues may stem from faulty CO2 application (amount/flow etc.) vs. light intensity vs. fertilizer. You may want to do a pH profile. In addition, it may be helpful to post a full tank shot so we can see what's going on in your tank vs. algae, plant mass, drop checker etc.

Cheers,
Michael


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## plantnoobdude (19 Jan 2022)

plants classed as 'medium' will still benefit from more co2. 30-37ppm is fine.. but the reality is you probably have much less. ph kh charts are quite inaccurate and i'd trust your drop checker more. just make sure you're placing it correctly. it should be placed in an area that co2 bubbles cannot float into, and preferably a couple inches from substrate. 

high co2 and low/med light plus a rich dosing regime is a recipe for success. the reason you were noticing very fast growth in amazonia is probably because of the ammonia it leaches in the first couple of months, plants love that. in the first couple of months your plants had an abundance of N, from amazonia and K+ micros from your ferts, now that your substrate is starting to stop leaching, your tank is probably N-limited, which is why you're noticing slower plant growth.

so, my suggestions.
1. keep light low
2. co2, high
3. ferts, moderate (i'd recommend you swap to apt complete it should give you faster growth.)


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## meyscapes (19 Jan 2022)

Hi @MichaelJ,

Thank you for the welcome and for your reply! I’ve not heard of doing a PH profile before, so I’ll check that out - thanks for sharing. 

I’ve attached three photos of how the tank is looking as of today and the last photo is the tank back in November. 

I had to remove a lot of the tall background plants last weekend due to algae growth on them and being too tall for the tank. 

I only changed the position of the drop checker today, but I think I need to adjust it still.

Thanks,

Melissa


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## plantnoobdude (19 Jan 2022)

meyscapes said:


> Hi @MichaelJ,
> 
> Thank you for the welcome and for your reply! I’ve not heard of doing a PH profile before, so I’ll check that out - thanks for sharing.
> 
> ...


drop checker looks a bit more on the blue side. i'd bump it up a touch. till it looks like this


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## meyscapes (19 Jan 2022)

Hi @plantnoobdude,

Thank you for your reply!

That’s interesting to hear, a lot of what I read today was saying that drop checkers aren’t very accurate as they show how much Co2 was in the water a couple of hours previous to the time that you’re viewing them. I only discovered about the positioning of them today, so I will adjust it. I didn’t realise it had to be in an area where Co2 bubbles can’t get into it. I use an inline diffuser, so there are often fine bubbles everywhere when the Co2 is on. I’ll have a look and see if I can readjust it, thanks for that tip!

That makes sense. This is my first time using ADA Amazonia and I did a dark start for a few weeks to avoid the largest amount of leeching that starts at the beginning. I wasn’t sure how long it lasts though overall, so haven’t known when to switch the ferts! I have APT complete so will make the switch over to this and see if it makes any difference.

I added some photos in another reply above btw to show the condition of the tank currently. 

Thank you for the help!


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## meyscapes (19 Jan 2022)

plantnoobdude said:


> drop checker looks a bit more on the blue side. i'd bump it up a touch. till it looks like this
> View attachment 180325


Not sure if it would make much difference but I took the photo 4 hours after Co2 had turned off. The lighting in the photo is a bit funny as well as my living room light was on, which made the white walls behind the tank look purple/blue, so there’s a bit of a colour discrepancy 🤷🏻‍♀️ I keep an eye on the drop checker and usually it’s a light green. Thanks though!


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## plantnoobdude (19 Jan 2022)

meyscapes said:


> That’s interesting to hear, a lot of what I read today was saying that drop checkers aren’t very accurate as they show how much Co2 was in the water a couple of hours previous to the time that you’re viewing them. I only discovered about the positioning of them today, so I will adjust it. I didn’t realise it had to be in an area where Co2 bubbles can’t get into it. I use an inline diffuser, so there are often fine bubbles everywhere when the Co2 is on. I’ll have a look and see if I can readjust it, thanks for that tip!


that is true, but it just means that you need to make sure the drop chcker is a nice green colour within an hour or two after the lights have been on. other than that i think drop checkers are more accurate, because methods that calculate co2 based on ph can be skewed by many other factors, such as new soil, kh swing from rocks leaching, wood, nitrification. 

tank looks very nice!


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## meyscapes (19 Jan 2022)

plantnoobdude said:


> that is true, but it just means that you need to make sure the drop chcker is a nice green colour within an hour or two after the lights have been on. other than that i think drop checkers are more accurate, because methods that calculate co2 based on ph can be skewed by many other factors, such as new soil, kh swing from rocks leaching, wood, nitrification.
> 
> tank looks very nice!


That’s true, the soil itself buffers my PH! I’ll see how the drop checker looks tomorrow now that it’s in a different position. I’ll probably do both tests and see they compare to each other. Hopefully once I get the co2 right, along with the nutrients the plants will pick up again 🤞🏼

And thank you! 😄


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## meyscapes (19 Jan 2022)

Just to update, I decided to test my nitrates and phosphates and it seems I have 30-40ppm of nitrates and 2-3ppm of phosphates. 

I’m not too familiar with how many phosphates I should have vs nitrates…would this be considered too high overall?


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## plantnoobdude (19 Jan 2022)

meyscapes said:


> Just to update, I decided to test my nitrates and phosphates and it seems I have 30-40ppm of nitrates and 2-3ppm of phosphates.


instead of hobbyist grade test kits, i'd look for a local water report


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## meyscapes (19 Jan 2022)

plantnoobdude said:


> instead of hobbyist grade test kits, i'd look for a local water report


I use a mix of 60% RO and 40% tap water in my tanks, so it’s not all tap. I checked my local water report last week and couldn’t find phosphate levels on there, but there was 20ppm of nitrates.


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## erwin123 (20 Jan 2022)

its important for the drop checker to be green and not turn yellow, but a drop checker can be 'green' and the CO2 levels could still be unstable. That's where pH measurement comes in.


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## meyscapes (20 Jan 2022)

erwin123 said:


> its important for the drop checker to be green and not turn yellow, but a drop checker can be 'green' and the CO2 levels could still be unstable. That's where pH measurement comes in.


Yes that’s what I’m wondering. I’m going to try and get an idea of my PH profiling now after the suggestions and seeing other threads on here. Hopefully it’ll help me get a better idea of what’s going on in the tank and I can go from there, thanks!


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## dw1305 (20 Jan 2022)

Hi all,


meyscapes said:


> and couldn’t find phosphate levels on there


There is <"no legal limit for orthophosphate (PO4---)"> in tap water, so the water companies don't report it (they can't be in breach of the limit, there isn't a limit).  

All water companies add some PO4--- to their water for <"phosphate induced metal stabilisation">, (<"PIMS for control of "plumbosolvency">). Because you live in London your tap water is likely to <"contain enough PO4---"> to support some plant growth, but it may still be <"Liebig's limiting nutrient">.

<"Phosphate is a compound"> for which <"hobbiest test kits should be fairly accurate">, I haven't tried it but I think @jaypeecee has used the <"JBL low range test kit">.

cheers Darrel


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## arcturus (20 Jan 2022)

meyscapes said:


> Hi @plantnoobdude,
> 
> 
> That’s interesting to hear, a lot of what I read today was saying that drop checkers aren’t very accurate as they show how much Co2 was in the water a couple of hours previous to the time that you’re viewing them. I only discovered about the positioning of them today, so I will adjust it. I didn’t realise it had to be in an area where Co2 bubbles can’t get into it. I use an inline diffuser, so there are often fine bubbles everywhere when the Co2 is on. I’ll have a look and see if I can readjust it, thanks for that tip!


Yes, drop checkers do not show the real-time conditions of the tank and are quite sensitive to positioning. And, like any other colour based test, they are not easy to read. But they are much more accurate than ph/dKH tables. Despite all these limitations, they are the best tool you can use to gauge the CO2 levels. As several others suggested, do a pH profile (i.e. use a properly calibrated pH probe to (1) pH measure the pH of degassed water, (2) measure the pH of the tank water every hour or so, starting when before CO2 injection and the photoperiod starts, and until the end of the photoperiod).


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## meyscapes (20 Jan 2022)

arcturus said:


> Yes, drop checkers do not show the real-time conditions of the tank and are quite sensitive to positioning. And, like any other colour based test, they are not easy to read. But they are much more accurate than ph/dKH tables. Despite all these limitations, they are the best tool you can use to gauge the CO2 levels. As several others suggested, do a pH profile (i.e. use a properly calibrated pH probe to (1) pH measure the pH of degassed water, (2) measure the pH of the tank water every hour or so, starting when before CO2 injection and the photoperiod starts, and until the end of the photoperiod).


Thank you! This is what I’m doing today and I have a calibrated PH probe to check it with. 

I’ll update this thread at the end of the day with the results.


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## jaypeecee (20 Jan 2022)

dw1305 said:


> I haven't tried it but I think @jaypeecee has used the <"JBL low range test kit">.


Hi Everyone,

Yes, I have been a user of the JBL PO4 (phosphate) _sensitive_ test kit for several years and this kit continues to serve me well. Now, that may sound like I don't replace expired reagents! Needless to say I do. The measurement range for this kit is <0.02 to 1.8 ppm.

JPC


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## jaypeecee (20 Jan 2022)

plantnoobdude said:


> instead of hobbyist grade test kits, i'd look for a local water report


Hi @plantnoobdude

That's OK for knowing what's coming out of someone's tap. But it's not much good to an aquarist who wants to know what's in his/her tank. That's where a decent test kit is very helpful. And a water company test report will indicate minimum, mean and maximum values of water parameters. But, it will not indicate values for the moments when you need them. Furthermore, if I look at my water report for 2018, for example, and check out iron, the minimum was 3.00 micrograms/litre and the maximum was 253.00 micrograms/litre.

As Darrel (@dw1305) explains below, some parameters of interest to we aquarists are not available.



dw1305 said:


> There is <"no legal limit for orthophosphate (PO4---)"> in tap water, so the water companies don't report it (they can't be in breach of the limit, there isn't a limit).



There are other examples of excluded water parameters that may be of importance to aquarists. I don't think silicon (as silicic acid) is included in water company reports.

JPC


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## meyscapes (20 Jan 2022)

jaypeecee said:


> Hi Everyone,
> 
> Yes, I have been a user of the JBL PO4 (phosphate) _sensitive_ test kit for several years and this kit continues to serve me well. Now, that may sound like I don't replace expired reagents! Needless to say I do. The measurement range for this kit is <0.02 to 1.8 ppm.
> 
> JPC


Good to know! I’m quite new to testing phosphates and only tested them as I read about GSA appearing due to high level. 

I’m not really sure what range is beneficial for plant growth vs too high or low. Same goes for nitrates! On the kits 40ppm comes at towards the high end, but I’ve read mixed info online, some saying this is fine, some saying this is too high.


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## meyscapes (20 Jan 2022)

Hey everyone!

Thanks for your replies and advice so far, I really appreciate it.

So I had a go at doing the PH profiling today. First off, here’s some general info of my co2 and light schedule…

My BPS is 1.

Co2 turns on at 08.00.

Lights turn on at 10.00 and are at full power (40% intensity) by 10:30. I’m using a Chihiros WRGB2.

Co2 turns off at 16:00.

Lights start to ramp down at 17:30 and are completely off by 18:00.

Here are the PH readings from today:

08.00 7.2
10:30 6.9 
11:30 6.9 
12:30 6.8 
13:30 6.8 
14:40 6.8
15:45 6.7
17.00 6.8
18:00 6.9

From this, my understanding is that I need to increase my co2 amount (upping the bps?) to make the PH drop lower faster? Or perhaps I need to make the co2 turn on even earlier?

I may have to redo this test again at the weekend as it’s a bit hard to periodically do the tests on the hour in between work meetings, but I was curious to get a rough idea of what my co2 today and it was interesting to see!


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## meyscapes (20 Jan 2022)

I realised I should have taken photos of the drop checker earlier this morning too, but I’ve attached a couple of photos how they looked this afternoon. 

This first photo is the colour of the drop checker at 1:30pm and the second photo is of it at 15:45pm! 

The position of the drop checker is in an area where I think there is the least flow and I put it here last night (with fresh ph solution) on purpose as a test. I’m thinking to buy a second drop checker to test different areas of the tank.


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## Hufsa (20 Jan 2022)

meyscapes said:


> Good to know! I’m quite new to testing phosphates and only tested them as I read about GSA appearing due to high level.


Could it be the other way around? I have always seen it advised as "GSA means you should -increase- your phosphate dosing".



meyscapes said:


> I’m not really sure what range is beneficial for plant growth vs too high or low. Same goes for nitrates! On the kits 40ppm comes at towards the high end, but I’ve read mixed info online, some saying this is fine, some saying this is too high.


Its a bit of a contested subject, the plant experts dont always agree with each other, and if you ask a fishkeeper vs a planted tank keeper about nitrates, you will get very differing answers. Since no one seems to have the answers for this yet, I have personally decided to stay somewhere in the mid zones, but you have to decide for yourself.


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## John q (20 Jan 2022)

meyscapes said:


> my understanding is that I need to increase my co2 amount (upping the bps?) to make the PH drop lower faster? Or perhaps I need to make the co2 turn on even earlier?


A lot depends on what your degassed starting ph is. Eg: if it's 7.8 then you'd probably want to start the gas an hour or so earlier to reach the 6.8 drop by lights on. If the degassed water is say 7.3 then you need to up the bubble rate a little bit to get that drop to go down quicker.

Looking at the drop checker and considering it's taking 2.5hrs to drop .3, I would think the bubble rate probably needs upping.

Yes, you are correct, it's best to make any changes when you are there to monitor it.

Edit: I should also add not to get overly fixated on the 1 point drop, if you manage to achieve a .9 drop and its stable from lights on to lights off then be happy with that for now.


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## dw1305 (20 Jan 2022)

Hi all,
I don't know if it is a possibility for you, but <"using rainwater"> gets around a lot of the issues with tap water.


meyscapes said:


> ....... for nitrates! On the kits 40ppm comes at towards the high end, but I’ve read mixed info online, some saying this is fine, some saying this is too high.


The problem with nitrate (NO3) is that <"you need to differentiate"> between the nitrate that has always been nitrate (in drinking water and added as potassium nitrate (KNO3) etc.) and the nitrate that results (<"_is the smoking gun of_">) from the oxidation of ammonia. We don't know at what level the the NO3- ion becomes toxic to most fish, but it is <"certainly a lot higher"> than 40 ppm NO3.

Because nitrate <"isn't easy to test for"> I use the the <"leaf colour and growth"> of a <"floating plant"> as a proxy for nitrate level.


meyscapes said:


> I’m not really sure what range is beneficial for plant growth vs too high or low.


I don't tend to worry too much, that is one of the great advantages of plants, they reduce the levels of all nutrients. Phosphorus (P) is one of the macro nutrients and plants convert phosphate (PO4---) in the water into plant tissue. When you harvest that plant matter you remove those nutrients from the tank.

Plants are much <"more efficient at nutrient removal"> than most aquarium based literature acknowledges.

cheers Darrel


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## meyscapes (20 Jan 2022)

Hufsa said:


> Could it be the other way around? I have always seen it advised as "GSA means you should -increase- your phosphate dosing".



Just had a look online and it seems that’s the case, I think. I did a test using the API Phosphate kit yesterday and it came out as 2-3ppm, so I don’t feel that that’s low anyway? Especially if the JBL kit only measures up to 1.8ppm.



Hufsa said:


> Its a bit of a contested subject, the plant experts dont always agree with each other, and if you ask a fishkeeper vs a planted tank keeper about nitrates, you will get very differing answers. Since no one seems to have the answers for this yet, I have personally decided to stay somewhere in the mid zones, but you have to decide for yourself.



That’s what I have trouble with 😅 I come from a fish keeping background to aquascaping and have always heard having 40ppm of nitrate to be bad, but obviously I understand having nitrates for plant growth is necessary. It’s just about finding the right amount/mid zone as you say. I might have to keep testing nitrates to see how they’re being used in the tanks. 



John q said:


> A lot depends on what your degassed starting ph is. Eg: if it's 7.8 then you'd probably want to start the gas an hour or so earlier to reach the drop by lights on. If the degassed water is say 7.3 then you need to up the bubble rate a little bit to get that drop to go down quicker.


Just to check, when you say degassed do you mean the PH level before the co2 is turned on? If so then it was 7.2. Thanks for giving those examples btw, it really helps me to understand the different contexts and solutions per one. I feel that you’re right in terms of probably needing to up the bps. Is it better to start by increasing it to 2 bps and just see how it does like that, incrementing again if necessary afterwards?

Also just to double check, the green in the second photo is the exact type of green I’m after? I use the co2 art droper checker and the photos online of drop checkers often show it looking more opaque/dark green, so it’s hard to for me to tell exactly 😅


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## meyscapes (20 Jan 2022)

dw1305 said:


> Hi all,
> I don't know if it is a possibility for you, but <"using rainwater"> gets around a lot of the issues with tap water.
> 
> The problem with nitrate (NO3) is that <"you need to differentiate"> between the nitrate that has always been nitrate (in drinking water and added as potassium nitrate (KNO3) etc.) and the nitrate that results (<"_is the smoking gun of_">) from the oxidation of ammonia. We don't know at what level the the NO3- ion becomes toxic to most fish, but it is <"certainly a lot higher"> than 40 ppm NO3.
> ...


I haven’t used rainwater, but I’ll look what you shared. I just assumed I probably shouldn’t as I live in London and because of all of the pollution etc 😅

That’s really interesting to know, thank you for sharing those links! I hadn’t heard of using the leaf colour to compare before, but I do use floating plants and they grow very quickly! To be honest all of the plants were growing very quickly until recently and it’s since then that the algae has grown and I’m needing to find out the cause in order to balance my tank.   

As I mentioned in my last reply I initially came from more of the fish keeping side (mostly Bettas) and so I’m not used to the higher nitrates as this is always stressed as being really bad for the fish. Thank you for breaking it down and explaining the difference, it definitely helps be to get a better perspective on how I should interpret the test readings.


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## KirstyF (20 Jan 2022)

Hi There

To get your de-gassed level, take a sample from your tank and then let it sit for 24hrs in an open topped container and then take the PH. That’s your starting level.

You can speed this up by putting the sample in a bottle and just keep shaking it and then taking readings periodically until the reading stops changing. Potentially quicker but a bit of a faff (not to mention the arm ache 😊


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## arcturus (20 Jan 2022)

meyscapes said:


> Good to know! I’m quite new to testing phosphates and only tested them as I read about GSA appearing due to high level.


There are several discussions about phosphates and algae here <at ukaps> and on  plantedtank forum . Also read this <Barr report> . There are tanks using high concentrations of phosphates, which have no GSA or other algae. It is more likely to trigger algae with a phosphate deficiency than with an excess of phosphates.


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## John q (20 Jan 2022)

No your degassed ph means what the ph of the tank water is when there's no extra co2 in it. To find out what this is you can either put some tank water in a glass and leave it sitting for 24hrs, then test the ph, or you can put some tank water in a lidded jar/tub and shake the living daylights out of it for 15 mins (I open it and re shake a few times)then test the ph of that water.

Yes that 2nd picture looks good to me.

Edit: Just like @KirstyF  says lol.


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## KirstyF (20 Jan 2022)

John q said:


> Edit: Just like @KirstyF says lol.



Great minds think alike. 😉😂


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## meyscapes (20 Jan 2022)

KirstyF said:


> To get your de-gassed level, take a sample from your tank and then let it sit for 24hrs in an open topped container and then take the PH. That’s your starting level.





John q said:


> put some tank water in a glass and leave it sitting for 24hrs, then test the ph, or you can put some tank water in a lidded jar/tub and shake the living daylights out of it



Ohh I see! I think I’ll take a sample and leave it out for 24 hours. I plan to do the profile again over the weekend when I can be more accurate for the time - plus the amount of shaking needed to test the nitrates on the API test kit is already enough for me 😂



John q said:


> Yes that 2nd picture looks good to me.



Great, I’ll keep an eye to match that level then. Thank you!


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## meyscapes (20 Jan 2022)

arcturus said:


> There are several discussions about phosphates and algae here <at ukaps> and on  plantedtank forum . Also read this <Barr report> . There are tanks using high concentrations of phosphates, which have no GSA or other algae. It is more likely to trigger algae with a phosphate deficiency than with an excess of phosphates.


Good to know and thanks for sharing! I have a lot of reading to do 😄


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## jaypeecee (22 Jan 2022)

meyscapes said:


> Especially if the JBL kit only measures up to 1.8ppm.


Hi @meyscapes 

Please take a look at:






						Phosphate in tapwater
					

I know many dismiss the accuracy of test kits but I find JBL more reliable provided you follow the instructions and apply some common sense. Anyway my result was immediately dark blue and the scale of JBL only goes to 1.8ppm and my assumption was that this was high and possibly an issue?  Hi...



					www.ukaps.org
				




I've also just discovered that JBL have another higher range phosphate test kit (for Koi/ponds) as shown here:

ProAquaTest Phosphate PO4 Koi Test Kit and here:









						JBL PROAQUATEST PO4 Phosphate koi
					

Reliable monitoring of the water values in koi ponds: determines the algae nutrient phosphate from <0,1 up to 10 mg/l




					www.jbl.de
				




Hope that helps.

JPC


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