Newbie in panic mode

[Clare]

Hello Everyone,

I’ve just gotten back in to the hobby after having to decommission my planted tank 18 months ago.

I thought I knew what I was doing, (everything went so smoothly last time I set-up a tank) and a couple of weeks in to it have brown algae everywhere (taking deep breaths, telling myself “it’s just diatoms….it’ll be ok”!)… but last night I noticed cyanobacteria over large sections of the substrate! Aaaaaaaahhh!!!

(No fauna at the moment. I put shrimp in and they all ended up in the sump and/or dead, which I also find unsettling, to say the least!!!)

So have jumped back in to this trusty forum to revise what I should be doing with lighting/CO2/ferts in the early stages of a planted tank!

I can’t find the appropriate thread/forum for this. Can someone please direct me to the right spot?

Thanks so much. (It’s fair to say I am in full panic mode).

 

[techman81]

I'm not one of the real experts here but a couple things I can say:

1. I think where you've posted is fine and it will be seen by those that can best help.
2. The real experts can help more if you provide some photos, all of your water parameters, lighting parameters, and fertilizer and CO2 details.

 

[Koan]

Here's a great discussion

I've recently also had great experience with Ultralife

cyanobacteria.1953/post-18205">

Post in thread 'Cyanobacteria'

Jun 27, 2025

I've been slowly starting a multi-year campaign to get people to understand Cyanobacteria (BGA) better. There's a lot of misinformation in this hobby, but it's 2025, and times are changing. So let's give it a try! There will be a simple summary at the bottom.

Understanding Cyanobacteria (blue-green slime algae, BGA):​

Cyanobacteria are a special "algae" in aquaria because they are actually bacteria. These bacteria can utilize free N2 nitrogen gas from the atmosphere to provide the necessary Nitrogen for growth (source, source). Approx 78% of regular...

• Naturescapes_Rocco

• 
• 

 

[Mr.Shenanagins]

Ditto on ultralife

 

[Naturescapes_Rocco]

Hi Clare, just for me to keep gathering data, can you tell us what your Nitrate reading is for this tank?

 

[Clare]

Hello Everyone,

Thanks for your replies. I'd forgotten what a great group this is!

Test results from a day or two ago from LFS were:

Ammonia <0.25
Nitrite 0
Nitrate 0 - 5
Kh low (LFS guy didn't say how low)

I'll repeat today, and also test for Phosphate

Tank details are:

Gear:

• 6 by 2 by 2 foot tank with sump - overall capacity is about 750L (a lot of DW, substrate, media, so it's hard to say specifically)
• Peninsula shape tank, which can make adequate circulation through the tank a bit tricky (as outflow and intake are in the same spot in the tank - at the top on one end)
• Return pump max capacity at (return head height of 1.35m) is 3200L/hr
• Lighting - "Make My LED" WRGB panel with 90 degree beam for freshwater plants (I've had this light for about 5 years) - capable of 126PAR at 60cm depth to substrate (320PAR at 15cm)
• CO2 - Yidao reactor on its own pump in sump (can easily achieve down to yellow on drop checker)

Substrate:
- Master soil base with play sand capping (the sand was washed as much as possible, but some areas still has dust in it, as seen when it is disturbed)

Planting:

• deliberately all easy to grow plants
• various epiphytes - java ferns, bolbitis, anubias, one sneaky buce
• various mosses
• loads of crypts and swords
• no stems, as I hate trimming stems - (but have ordered some now as I'm worried that might have something to do with the problem?)

Fertiliser:

• Phat Pro - I haven't used this before but my LFS had it! - dosing every second day
• plan to switch to brand I'm familiar with - LCA All-in-one soon

Lighting:

• for 2 weeks, has been on 10 - 20% resting on tank rim, on one side of the tank (DW emerges down the centre of the tank) - about 50cm from substrate surface
• 5 days ago it was lifted to hanging kit, about 30cm above water surface - about 70 -80cm above substrate surface - I had increased to 20 - 30% to accomodate for height
• have reduced right down to 5% now that I've seen the cyano-bacteria

Flow:
- had pump on maximum, but shrimp weren't coping with the flow near the return outlet, so flow reduced to very low - just so I could see some movement of plants at the far end of the tank

Regimen:
- 50% water change at least weekly

Tank history:

• cycled before planting (I think.... I wasn't being too obsessive about it....just had it running for a couple of weeks, dosing stability and ammonia while deciding on DW layout etc - all parameters good at time of planting ie no ammonia etc)
• Plants went in 2.5 weeks ago
• lighting at this point was 10% for 6 hrs, but lying on rim on one side of the tank (whilst waiting for hanging kit to arrive) - ie. one side of tank got a lot more light than the other side
• started ferts immediately at recommended dose
• diatoms (?brown algae)++ very quickly on some of the DW pieces - (not surprising, as this happened ++ when soaking the DW)
• CO2 started after a couple of days - still dialling this in - using drop checker as pH probe is broken! - have mostly been overdoing it with drop checker too yellow, so am trying to pull back

Plant health:
- planted plants a looking good, and growing well (especially the swords, holy moly)

• epiphytes are going slowly, as expected
• mosses are gathering brown algae/diatoms - might just remove it all, and put back in when tank has settled

Fauna:

• added 30 shrimps a week ago - they all quickly ended up in the sump or dead! I acclimated them slowly with drip-method, and they were ok when they first went in. Seem to die by being stuck in the sump foam, or when I returned them to the main tank. Wondered if the temp difference killed them? - have been worried there is a toxin of some sort in there - I had cleaned the tank and DW with vinegar, but rinsed it very well...
• one tiny BN went in (happened to be very catchable from my other tank) and is still going strong
• have another batch of shrimps due in the next few days
• keen to put otos in, but am worried there is an issue with the water

Re cyanobacteria:

• noticed this two days ago - initally thought it was GSA on the substrate, but when I started siphoning I realised it was covering the sand substrate, and ?on some rocks and DW - it was mostly a very light brown colour, with some typical green specks developing.
• this seems confined to the side of the tank where the light had been resting on the rim for 2 weeks (whilst waiting for hanging kit)

Sooooo, the factors I am wondering about:

• what process do experts use to balance out their lights/ferts/CO2 when starting up a tank? eg. always start with x% lighting, and x% ferts etc, then increase which at what rate.....?
• what is appropriate lighting, fert, CO2 regimen for this type of planting, in first few weeks/months?

- nitrate is low, but I am dosing for a fully planted tank, so not sure if I should increase or decrease it?

• is there such a thing as "too much CO2" when it comes to algae?

• need to get better circulation of flow throughout the tank (cyano-bacteria like stagnant water, I think?) without blasting shrimp - I had a gryo I can put in
• how to prevent shrimp from being sucked in to sump? (Last time I had loads in the sump, but they were breeding there, so could be put back in the main tank, and enough were staying in the main tank to help with algae - but there was a lot more plant volume for them to live in)
• how soon do people add livestock eg. clean up crew?

Thanks so much for any advice you may have!

(Have attached some images - the rocks are white with black specks, so the algae is hard to see - some of it is just green algae I think, but but there is brown stuff which I think is cyanobacteria, as it came of in sheets....)

 

[Sb1415]

Welcome back to the hobby. It seems like you have lot of experience in this hobby based on your setup so i don't have much to say and will be waiting for the usual suspects to comment (which they always do - which is great about this forum )

That said, i would recommend reading the 2Hr aquarist website as usual since it will probably cover everything that you would want know.

I have no experience with master soil base but looks like aquasoil. It doesn't seem like it is leaching a ton of ammonia, but guess it could still be causing the issue and you might need a temporary setup with quick growing stem plants to absorb nutrients, and stabilize tank. Crypts and swords do take some time to stabilize and melt as you probably know. I have heard many people using temporary stem plants like Pearlweed to stabilize tak 3 Hacks when starting a new tank.

I know this might become a point of debate and others with more experience could probably comment; but I don't think the plant list that you currently have need ton of water column fertilizer. Both the crypts and swords would do great with just root tabs, most of my Java ferns did well without any water column fertilizer but did have a good amount of fish load. I am not sure of bolbitis and mosses. Maybe you might need to fine tune your ferilizing schedule - I like this article from the 2 hr aquarist which i think has a good balance of discussion on different types of fertilizing - Algae Control 101: How to prevent algae in an aquarium?.

Last but not least, i might have missed it but what kind of water do you use ? and do you re-mineralize it ?

 

[BenB]

Have you started a journal? This sounds like a great set-up.

 

[Clare]

Welcome back to the hobby. It seems like you have lot of experience in this hobby based on your setup so i don't have much to say and will be waiting for the usual suspects to comment (which they always do - which is great about this forum )

That said, i would recommend reading the 2Hr aquarist website as usual since it will probably cover everything that you would want know.

I have no experience with master soil base but looks like aquasoil. It doesn't seem like it is leaching a ton of ammonia, but guess it could still be causing the issue and you might need a temporary setup with quick growing stem plants to absorb nutrients, and stabilize tank. Crypts and swords do take some time to stabilize and melt as you probably know. I have heard many people using temporary stem plants like Pearlweed to stabilize tak 3 Hacks when starting a new tank.

I know this might become a point of debate and others with more experience could probably comment; but I don't think the plant list that you currently have need ton of water column fertilizer. Both the crypts and swords would do great with just root tabs, most of my Java ferns did well without any water column fertilizer but did have a good amount of fish load. I am not sure of bolbitis and mosses. Maybe you might need to fine tune your ferilizing schedule - I like this article from the 2 hr aquarist which i think has a good balance of discussion on different types of fertilizing - Algae Control 101: How to prevent algae in an aquarium?.

Last but not least, i might have missed it but what kind of water do you use ? and do you re-mineralize it ?

Ha, don't be fooled. Definitely "all the gear and no idea"!

Yes, will dive in to 2Hr aquarist website. Will also revisit George Farmer's resources, as haven't checked that out again...

I think you are right re ferts. The swords and crypts are doing incredibly well actually. Some of the swords have tripled in size, and one is already sending out a runner (or flower??). I've not have swords before, and am really impressed by them.

Have some stems in the mail to use exactly as you suggested (and a little hydrophila pinnatifida).

Thanks again...

(Also would be grateful if anyone could recommend a pH controller that doesn't cost a house!)

 

[Clare]

Here's a great discussion

I've recently also had great experience with Ultralife

Post in thread 'Cyanobacteria'

Jun 27, 2025

I've been slowly starting a multi-year campaign to get people to understand Cyanobacteria (BGA) better. There's a lot of misinformation in this hobby, but it's 2025, and times are changing. So let's give it a try! There will be a simple summary at the bottom.

Understanding Cyanobacteria (blue-green slime algae, BGA):​

Cyanobacteria are a special "algae" in aquaria because they are actually bacteria. These bacteria can utilize free N2 nitrogen gas from the atmosphere to provide the necessary Nitrogen for growth (source, source). Approx 78% of regular...

• Naturescapes_Rocco

• 
• 

Aha! Have now read this, and wonder if I should UP my ferts instead of decrease!!??

 

[Naturescapes_Rocco]

Aha! Have now read this, and wonder if I should UP my ferts instead of decrease!!??

Yes, but there's more to it than that!

Read it all again, let me know what questions you have.

Cyanobacteria thrive when you have little to no NO3. Your plants cannot outcompete cyano when they're missing NO3.

Increasing your NO3 (and other ferts, too) while doing water changes and treating with Ultralife is a guaranteed way (in my many-times-proven theory!) to get rid of cyanobacteria.

It is occurring in the first place, because your NO3 is bottoming out. That makes sense; NO3 is the first thing plants use up besides carbon.

 

[gjcarew]

Do you have any pictures of the cyanobacteria? Everything looks OK to me. I'd say just keep fertilizing, doing water changes and cleaning up algae that pops up (it will pop up).

People talk about a "balanced" aquarium but the truth is there is no single point of balance. All you really need is to create a stable environment where your plants can grow, and they will eventually outcompete the algae. You will be worse off changing a bunch of things, because plants need time to adjust to new conditions. And when plants aren't thriving, that gives algae a foothold.

So I know it's probably not helpful but just stop freaking out, be consistent, and things will get better.