Plants turning black

[D.Bezinski]

Hi All,

I am new to the hobby and need help identifying the type of algae I am dealing with. Here is some more information about my tank:

1. Size of tank in litres - 200l
2. Age of the set - up - 10 months
3. Filtration - Oase BioMaster 600. Using the original Oase filter media + 1L Seachem Matrix + 250ml Seachem Purigen
4. Lighting and duration - SOLIKU 90cm 48W Full spectrum LED light., 6500K. Sunrise 13:00-15:00, 100% 15:00-19:00, Sunset 19:00-21:00
5. Substrate - Fluval Stratum
6. Co2 dosing or Non-dosing - Dosing CO2
7. Fertilizers used + Ratios - I've tried different fertilizers and I've always had this issue (shown in the pictures) with the plants. I used TNC Complete, API Leaf Zone, Tropica Premium, Tropica Specialised. I was dosing 5ml API Daily then i switched to Tropica Premium (2 pumps daily) with no result. The I've decided to try Tropica Specialised (2 pumps daily) but I think the problem got worse. I also tried dosing daily API Leaf zone combined with Tropica Premium. Currently I am dosing just Tropica premium (1 pump) every other day.
8. Water change regime and type - Water change 40% weekly using tap water. Tried 40% twice per week. Here are some numbers
Tank water before water change:
Ph - 7.6 - 7.8
Ammonia - 0
Nitrite - 0
Nitrate - 40
Phosphate - 0.5-1
Kh - 10
Gh - 16

Tap Water:
Ph - 7.6 - 7.8
Ammonia - 0
Nitrite - 0
Nitrate - 40-50
Phosphate - 0.25 - 0.5
Kh - 10
Gh - 16
9. Inhabitants - 16 Neon/Cardinal Tetras, 12 Rummy Nose tetras, 6 Otocinclus, 6 Siamese algae eater, 4 Corrys, 10 amano shrimps

Any help will be appreciated.
Thank you.

 

[Konsa]

Hi
Tell us more about your CO2 injection.
What time it starts compared to your photoperiod, have you done Ph profile or dropchecker only(colour of it if so as the day goes)
Any particular reason for such long Sunrise and Sunset periods?
Regards Konstantin

 

[D.Bezinski]

Hi Konstantin,
I am injecting DIY CO2. Currently i am on 2 bubbles p/sec. The dropchecker is green (slightly blue-ish). Tried injecting more 3-4 bubles. Also, tried injecting less (1 bubble) but the dropchecker is staying blue. I forgot to mention that i am also adding Easy-life EasyCarbo. Started with 5ml daily, now 10ml daily. Turning CO2 on 2h before the lights go On and turning it off 30 min before the lights go off.

No reason for the long sunrise and sunset. For some reason i cant figure out how to change this setting on the light. My tank is Fluval Roma 200 and it came with a led light and the sunrise and the sunset was set to 30min. I thought i will try with more powerful light but that didn't help
Regards Dimitar

 

[kayjo]

You have very high nitrates in your tap water. Not healthy even for human consumption.

I notice that your nitrates actually drop or (stay the same) between water changes even though you are adding fertilizer. I assume that is due to the Purigen.

You have ample nitrate in your tap water that you don't need to add more. You may get by with the phosphate level too. Have you tried a fert that does not contain nitrate or phosphate like APT Zero?

 

[Konsa]

Hi
before you jump on the what nutrient deficiencies/toxicity etc etc train it is clear that you do not have stable CO2 injection and with long Sunset and Sunrise(do now know what intensity those are may not meet plants minimum light compensation point so they are not doing any photosynthesis/growing during that time )setting complimented with 4 h at 100% is where your troubles are.
Algae has much less light requirement than plants.
Post full front tank shot(video better) to get better idea about your setup.
Try to find how to sort your light settings so its 30min ramp up and down and 6 h of 50% photoperiod.
What is your drop checker solution?In tank difuser or atomizer for CO2(brand,)?
Regards Konstantin

 

[D.Bezinski]

You have very high nitrates in your tap water. Not healthy even for human consumption.

I notice that your nitrates actually drop or (stay the same) between water changes even though you are adding fertilizer. I assume that is due to the Purigen.

You have ample nitrate in your tap water that you don't need to add more. You may get by with the phosphate level too. Have you tried a fert that does not contain nitrate or phosphate like APT Zero?

Hi Kayjo,
THank you. I was thinking to try TNC Lite next because it does not contain nitrate and phosphates
Regards Dimitar

 

[Konsa]

Hi
Stick to Tropica specialised or whatever complete fertiliser you have (You need macro nutrients for plant growth)and see my earlier post.Change one thing at a time and give plants time to react(4 ish weeks) before making more changes.Your CO2 and light is the priority here😉
Regards Konstantin

 

[Konsa]

I notice that your nitrates actually drop or (stay the same) between water changes even though you are adding fertilizer. I assume that is due to the Purigen.

Hi
Purigen has impact on organic waste and will not touch any added Nitrates or other ferts.
Regards Konstantin

 

[D.Bezinski]

Hi
Stick to Tropica specialised or whatever complete fertiliser you have (You need macro nutrients for plant growth)and see my earlier post.Change one thing at a time and give plants time to react(4 ish weeks) before making more changes.Your CO2 and light is the priority here😉
Regards Konstantin

Hi Konstantin,

Thank you for your reply. Please see the attached. I am using in tank diffuser.
Regards Dimitar

 

[Konsa]

Hi
I see your diffuser and drop checker are close to each other.You may not get accurate reading there.Move them so they are on opposite sides of the tank.
Maybe if you put the diffuser under the circulation power head so it sucks the bubbles it will help with spreading(dissolving) the CO2 better.
200l is not a small tank as far as CO2 is concerned (3-4 bubles may be insufficient)and CO2 in large tanks is more challenging.
I see you have some green algae on some leaves too .
Im sure you can turn things arround.Sort your Lights and improve CO2 as a start.Then manual removal and good elbow grease.
Do not worry about ferts just dose complete fertilizer to cover them so you can focus on the important stuff CO2 stability, flow and distribution and good lighting (I don't mean strong lighting tho).You need the find the right balance between those in your system.
Ferts do not cause algae even in excess. I dose my tank daily at nearly full EI and I don't even have CO2 on it so plenty of excess ferts with me 😉
Regards Konstantin

 

[D.Bezinski]

Thanks Konstantin.
I will make these changes and I will see how it goes 🙂 appreciate your help

 

[dw1305]

Hi all,

notice that your nitrates actually drop or (stay the same) between water changes even though you are adding fertilizer. I assume that is due to the Purigen.

It is more likely to be the plants. Plants are very effective at reducing the levels of all <"forms of fixed nitrogen"> (N).

Purigen has impact on organic waste and will not touch any added Nitrates or other ferts.

I also don't think Purigen will have any effect on nitrate (NO3-) ion levels, it removes compounds that are, at least, an <"order of magnitude larger than nitrate ions">.

Stick to Tropica specialised or whatever complete fertiliser you have (You need macro nutrients for plant growth)and see my earlier post.Change one thing at a time and give plants time to react(4 ish weeks) before making more changes.

I'd stay with a <"complete fertiliser mix">, you should be able to get <"nitrate levels from your water company">, they have an analytical lab and will supply accurate values.

cheers Darrel

 

[D.Bezinski]

Thanks Darrel.

I managed to get a water quality report from my water supplier and the nitrates levels are 50mg/l.
Should I try a fertilizer without nitrate, like Kayjo said?


Regards Dimitar

 

[sparkyweasel]

nitrates levels are 50mg/l.

Not according to that report. 🙂
19.77mg/l average, 27.6710 maximum, 3.35 minimum.
I would keep using complete fertiliser, nitrate won't cause you problems, lack of nitrate would.
Have a look at; Nitrate toxicity
I think @Konsa is right, you need to sort your lights and CO2 out.

 

[dw1305]

Hi all,

and the nitrates levels are 50mg/l.

The reports are a bit confusing, but the 50 mg/L (50 ppm NO3) is the regulatory limit ("Prescribed Concentration or Value" - PCV) for tap water. The values you are interested in are the ones @sparkyweasel quotes:

19.77mg/l average, 27.6710 maximum, 3.35 minimum.

The minimum value is quite interesting, you either got tap water <"from a different source">, or possibly nitrate levels got near the 50 ppm limit and you received a <"stripped supply">.

Should I try a fertilizer without nitrate

Difficult to say, looking at your water report most of the time your tap water is supplying ~20 ppm NO3, but some of the time it is supplying less than 1/4 of that. You could test your <"tap water for nitrate">, but there are issues with this, and simplest option is just to keep using a <"complete fertiliser mix"> (one including NO3).

Because you are adding CO2 you need consistent nutrient levels. I'm not a CO2 user so can't really help with that bit.

cheers Darrel

 

[D.Bezinski]

Hi all,
Really appreciate your help guys. Thank you.

What about my water hardness? Should I worry about this?

 

[dw1305]

Hi all,

What about my water hardness? Should I worry about this?

No, not really. The other bit of your water report should record the calcium and <"hardness value">.

If you live in the S.E. 2/3 of England you are likely to have hard, <"calcium (Ca) rich">, water, but with <"very little magnesium (Mg)"> in it.



Some plants <"grow better in hard water">, some won't grow, most <"commonly available plants"> are fine in either hard or <"soft water">.

cheers Darrel

 

[arcturus]

Hi all,
Really appreciate your help guys. Thank you.

What about my water hardness? Should I worry about this?

You state that you have Kh = 10 and Gh =16. Btw, did you get these values from the water analysis report? These values are not an issue per se but they are another reason why you really need to control the CO2 injection and amount of light as a first step. Your CO2 injection rate already seems low for a 200 l tank. But with this level of water hardness acting as a pH buffer, you likely have CO2 related issues. As suggested above, move the diffusor below the power head, reduce the light period and the ramp up/down period, and slowly increase CO2 injection. Ideally, get a pH probe to profile the pH while adjusting the CO2 injection rate and keep a close eye on the livestock.

 

[D.Bezinski]

You state that you have Kh = 10 and Gh =16. Btw, did you get these values from the water analysis report? These values are not an issue per se but they are another reason why you really need to control the CO2 injection and amount of light as a first step. Your CO2 injection rate already seems low for a 200 l tank. But with this level of water hardness acting as a pH buffer, you likely have CO2 related issues. As suggested above, move the diffusor below the power head, reduce the light period and the ramp up/down period, and slowly increase CO2 injection. Ideally, get a pH probe to profile the pH while adjusting the CO2 injection rate and keep a close eye on the livestock.

Hi Arcturus,
These Kh and Gh values are from my test (API Test kit). About the diffuser, I moved it below the power head but the result is not what you expect 🙂 The bubbles are going behind the power head straight to the top. I have to stick the diffuser to the front glass in order to work. It doesn't look good but i will leave it for now just to test.

Thanks everyone for the advice. I will sort out my light settings tonight and i will increase the co2. 🙂

 

[dw1305]

Hi all,

You state that you have Kh = 10 and Gh =16. Btw, did you get these values from the water analysis report?

These Kh and Gh values are from my test (API Test kit).

It is very likely that the actual dGH and dKH levels are the same, and probably somewhere near 16 dGH / 16 dKH.

This is because both dGH and dKH originate from dissolved limestone (CaCO3) and it supplies 1 : 1 dGH : dKH.

The 16 dGH is somewhere near the values you get for water that is fully saturated with Ca++ and 2HCO3- ions, via the <"carbonate ~ atmospheric CO2 equilibrium">. Our water comes from a limestone aquifer and <"is about 17dGH / 17 dKH">.

cheers Darrel