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Fighting the BGM

Aleman

Member
Joined
28 Mar 2022
Messages
81
Location
Blackpool, UK
I'm currently holding my own in my battle with the dreaded BGM (Blue Green Menace - aka cyanobacter), but the battle lines have been pretty static for a few weeks.

1. Size of tank in litres. Nominally 305L, but after losses due to substrate and hardscape it holds 240L
2. Age of the set - up. Flooded the tank in mid Jan 2022 (IIRC) after allowing the carpeting plants a dry start period
3. Filtration. Internal "Sump" type driven by a Sicce Syncra Silent 2.0 pump (2350L/Hr). Return via a spray bar
4. Lighting and duration. Two Dennerle Trocal LED 120 Units with a SuperFish 74 On FULL for 6 hours with a 2 hour ramp up and down (sort off)
5. Substrate. Lava Rock, Neutral gravel, capped with sand. 3Kg of Bioplast Terramineral as nutrient.
6. Co2 dosing or Non-dosing. CO2 injected with a CO2 Art Elite SE reg controlled by JBL Proflora pH Touch controller, pH set to 6.15 with a 0.1 hysteresis. Diffused using a 20" Cerges reactor. ... Some bubbles still get through to tanks, which is good as I can see flow to all parts of tank.
7. Fertilizers used & Ratios. EI Full using potassium nitrate, di potassium phosphate, and magnesium sulphate split into 14 doses over 7 days. Micros CSM+B, plus Fe EDTA
8. Water change regime and type. 50% weekly using RO water ... remineralised to 1KH and 2GH using Aqua Source GH/KH UP balancer
9. Plant list + When planted. Monte Carlo, S. Repens, lillaeopsis brazillensis, Eleocharis "mini" Dry start November 2021. Sagitaria subulata, M. mattogrossesense, E. reni, E hormanii L repens "super red" Mid January 22
10. Inhabitants. Currently 25 Bleeding Heart Tetras, 3 (was 9) Otocinclus, Amano shrimp (was 20, but who knows :D ), 2 King Koopa snails.
11. Full tank shot & Surface Image.
IMG20220424170307.jpg


The Clean Up Crew have pretty much dealt with the normal algae, and after reading a couple of threads here, I suspect if it was the toxicity of the BGA that did for my otos :bawling::bawling:. I've got a variety of forms, from the usual Blue Green, to Black, and even brown/red. I've had some success at keeping it in check using Blue Green Stain remover, but it keeps coming back. The moss on the back wall is full of black slime, the moss on the wood brown, and the montecarlo blue green, particularly on the glass. I've been lax in getting rid of the detritus, which probably doesn't help matters. To this end I've temporarily installed a SunSun HW3000 filter full of fine foam, filter woll and floss to act as a vaccum cleaner and I stir up the detritus manually. I'm also hoping it will keep the algae in check as it has a built in UV lamp so should prevent any cells in the water column from reproducing.

BG stain remover is a stop gap while I find out a real solution. Reading @jaypeecee's thread was interesting as it threw out some well known causes, and then @Dr Mike Oxgreen added some posts there which started me thinking.

1. Flow ... Its possible I have low flow in parts of the tank
2. Maintenance ... Yeah, this was a problem, but I'm hoping to have made that simple now, and at the moment it should have helped the flow problem.
3. Low/Unstable CO2 Levels ... Unlikely as it's controlled by the pH Touch controller within +- 0.1 units of the pH determined by the KH.
4. Light too much / too high ... could be, but lets leave that as set at the moment, as I am having issues with growing red plants, and really want the Myriophyllum to grow as fast as it should do.
5. Nutrients ... could be a problem as I've only really started EI in the last 4 weeks, having fallen foul of 30 year old knowledge that nitrate and phosphate are bad, so wasn't adding nutrients on a regular basis.

At my last water change the parameters were measured, using JBL test kits
Ammonia <0.05
Nitrite < 0.025
Nitrate 5
Iron 1.5
potassium 25
phosphate 2.4

These levels have been pretty much constant over the last couple of weeks, So my Nitrate is low, but it looks as though the plants are using what I'm adding which is sufficient for the plant mass currently, especially combined with that produced by the fish. One think @Dr Mike Oxgreen mentioned was that the nitrate to phosphate ratio was important, not just "low nitrate", mine is 2:1 and Mike says he has trouble with BGA if his drops below 5 to 1. As today is "Water Change Day" I'm thinking of adding 30ppm of ammonium nitrate, 4.62g (in addition to carrying on with my standard nutrient doses) This would take the NO3 to PO4 ratio up to 10 to 1, which would hopefully be maintained, if it drops quickly then that has to be an indication that I'm underdosing nitrate ... yes?

Anyone got any other suggestions or think that this is a bad idea?
 
Hi all,
I'm thinking of adding 30ppm of ammonium nitrate, 4.62g (in addition to carrying on with my standard nutrient doses) This would take the NO3 to PO4 ratio up to 10 to 1, which would hopefully be maintained, if it drops quickly then that has to be an indication that I'm underdosing nitrate ... yes?

Anyone got any other suggestions or think that this is a bad idea?
Don't, It is an <"absolutely terrible idea"> and likely to kill all your fish because of the <"ammonia / ammonium addition">.

cheers Darrel
 
As it happens I haven't done it yet, as I was playing groom to She and her horses :(

So what about adding 30ppm of a "Safe" nitrate source ... I have potassium nitrate, and I could always order Urea, indeed She may well have some in the chemical store at work :D
 
It sounds like the lack of ferts and detritus build up might have been the cause. The trouble with it, is that once you have BGA just fixing the underlying issue doesn't get rid, or at least not quick. I would suggest a blackout. That should knock it back and if your fixes have addressed the root of the problem it will stay away. Black out means covering the tank to block ambient lights and leaving the lights off. I'm not a CO2 user, so perhaps someone can comment on whether they switch it off in a blackout - I would imagine so. So water change pre-blackout, removing as much trace of it manually as you can (tooth brush/syphon), then blackout for a week, and fingers crossed when you uncover it.
 
I like the idea of a blackout, I think I'll do the water change add an additional 9.5g of KNO3, which should take the nitrate up to around 30ppm total. Then a blackout, feed the fish as normal??
 
Don't mess with Ammonium Nitrate - As Darrel said above, it will likely kill your livestock!

Your tank is only 3 months old but obviously not mature and stable yet - it's not uncommon to have an outbreak of BGA under those circumstances (I've had it). Look into your CO2 flow situation. Unstable and/or improper flow and distribution of CO2 and nutrients can cause this. Lack of maintenance as well, but your 50% weekly should suffice IMO IF your WC water parameters overall matches the tank water parameters - wide swings can cause algae problems. Also, your recent change of dosing regime could also be a trigger, but just keep it up and follow instructions for the product - perhaps front-load the weekly NPK fertilizers to your WC water - a lot of us are doing that with good results. As long you stabilize things regardless of your dosing regime - and you dont have any gross deficencies it should be fine. In the meantime, you might want to lower your light intensity. If your tank is unstable / immature too high light intensity will just exacerbate the problem.



Cheers,
Michael
 
I'm not sure I'd add add anything pre blackout as the plants aren't really going to do any growing in the dark so wont make use of it.
 
The reason I mentioned ammonium nitrate is that the % of TAN as free ammonium at pH 6.15 and 25C is 0.078%, surely not enough to cause a livestock issue. Sure, if for some reason my pH rises to above 7 then that may well cause an issue, but with the pH Touch controller maintaining the pH, thats not likely to happen, especially during a blackout.
 
The reason I mentioned ammonium nitrate is that the % of TAN as free ammonium at pH 6.15 and 25C is 0.078%, surely not enough to cause a livestock issue. Sure, if for some reason my pH rises to above 7 then that may well cause an issue, but with the pH Touch controller maintaining the pH, thats not likely to happen, especially during a blackout.
Hi @Aleman, How did you arrive at that number? at that low pH and temperature range a Total Ammonia reading in the <1 ppm should not be a cause of huge concerns - NH3 levels, as far as I can tell, would be <0.001 ppm.. However, I think the point is that your BGA issue is, considering the immaturely of the tank, much more likely to stem from other factors than your N : P ratio... (and you can safely tweak that by other means such by using KNO3, Mg(NO3)2 etc.). While ratios likely have merit under different conditions (I think they do...) - such as optimizing color and healthy growth of more challenging plants when overall tank conditions are otherwise very close to ideal, fighting a prevalent BGA issue in an immature tank by tweaking ratios is ... well... akin to rearranging the deck chairs on the Titanic. :)

Cheers,
Michael
 
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3 (was 9) Otocinclus

2. Maintenance ... Yeah, this was a problem, but I'm hoping to have made that simple now, and at the moment it should have helped the flow problem.

At my last water change the parameters were measured, using JBL test kits
Ammonia <0.05
Nitrite < 0.025
That all suggests to me that the tank ecosystem (in-tank and in-filter) is immature.
BGA is often associated with a build-up of organic waste.
I would increase the sze and/or frequency of water changes, at least until the tank matures.
hth
 
Hi @Aleman, How did you arrive at that number? at that low pH and temperature range a Total Ammonia reading in the <1 ppm should not be a cause of huge concerns - NH3 levels, as far as I can tell, would be <0.001 ppm.
Hi @MichaelJ, There are plenty of research papers with the data available, and calculators based on those models. This PDF is where I got the number from, the tables are badly laid out, but I think it's around page 3. I also stumbled across this article relating to the value in aquaria and ponds, this then links here. So using ammonium nitrate in my environment should be perfectly safe. Having said that though, It'll stay in its pot. I get what everyone is saying regarding immaturity of the tank, I'll step back and look at the big picture before microanalysing it :D
 
3. Filtration. Internal "Sump" type driven by a Sicce Syncra Silent 2.0 pump (2350L/Hr). Return via a spray bar
In pic you have skimmer in middle of tank, outlet to one side and lily pipe also 😵 Have you a full tank pic with the spay bar in action so we can see the surface agitation.

I had BGA in 500 litre most of the time, it was below the substrate level in a few small areas and never got out of control. Just like when you do a big maintenance and find a mass off BBA on rock hidden from normal view.
 
At my last water change the parameters were measured, using JBL test kits
Ammonia <0.05
Nitrite < 0.025
Nitrate 5
Iron 1.5
potassium 25
phosphate 2.4
Hi @Aleman

Additional to the above, what pH figures do you have and what is your water GH and KH? In the case of pH, it would appear that it's in the range 6.15 to 7 (ish) from the following...
The reason I mentioned ammonium nitrate is that the % of TAN as free ammonium at pH 6.15 and 25C is 0.078%, surely not enough to cause a livestock issue.

Sure, if for some reason my pH rises to above 7 then that may well cause an issue, but with the pH Touch controller maintaining the pH, thats not likely to happen, especially during a blackout.

JPC
 
One think @Dr Mike Oxgreen mentioned was that the nitrate to phosphate ratio was important, not just "low nitrate", mine is 2:1 and Mike says he has trouble with BGA if his drops below 5 to 1.
Hi @Aleman

I worked closely with "Mike" on this. The nitrate : phosphate ratio is more complex than it first appeared. No surprises there, eh!

JPC
 
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