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Blue Green Algae and Diatoms?

Well I also want rid of the duckweed for reasons of aesthetics & to avoid getting a green arm every time i put my hand in the water, but nevertheless it has a competitive advantage over other plants in terms of its access to CO2, and therefore takes up more nutrients. If I remove it there will be more nutrients available for other plants under the same dosing regime. (of course, they may not be nutrient- or light-limited; in which case removing it will have little effect)

You're right I never actually said what I was dosing. I'm now putting in 5ppm NO3 & .7ppm PO4, along with 2mls Easy-Life Profito and 5mls (double dosage) EasyCarbo. This is done daily.

Flow is the next issue to attack. Once I have that in place I can look at doing a big clean. Primarily the diatoms & BGA are caught up in the Java Moss, so I can remove the majority of them just by taking it out and giving it a good bath under tap water. Rhizo isn't so much of an issue, but green spot algae is starting to be (given I've only just started dosing PO4, I wasn't expecting this to disappear straightaway).
 
Hi,
5ppm daily of NO3 and 0.7ppm daily PO4 is a lot so there's no way that you don't have enough. How are you determining these values and what product is being used? Removing the duckweed also allows more light in the tank thereby raising the uptake requirements of the other plants. This sounds more and more like a flow/distribution issue based on those numbers.

Cheers,
 
Using KNO3 and KH2PO4 for both (dry powders purchased online, therefore unknown purity). Calculated ppm values based on 100% purity assumption and on estimated volume of water (tank vol - hardscape). Know that NO3 is roughly correct as tested shortly after first addition. By tested I mean I tested tap water & tank water. Both zero. Then added 10ppm KNO3 to tank water and waited an hour for it to mix. Tested 3 replicates, all roughly 10ppm after addition.

Didn't test phosphate as don't have kit but calculations are correct. Both PO4 & NO3 are mixed in the same bottle.

I agree that flow is the next major item to address. Was surprised I was getting turnover of just once an hour as this is only ~30% of the max flow rate I believe. The powerhead will then give me a turnover of 11x, which hopefully will be sufficient.

I'm not sure where exactly to put the powerhead in the tank. I have a 3D background glued internally to the back glass (was there when I bought it) which prevents attaching anything to the back. I think I'll start with putting it on the front left pointing along the front of the tank. The filter intake is visible in the pic on page 1 and the outlet is on the back just right of centre and pointing to the right. This creates an eddy on the right of the tank but not much movement elsewhere. Adding the powerhead on the left should create flow on the left side. I chose the front because there is a large bit of wood which would dissipate the flow if I put it at the back. My hope is that the powerhead is strong enough to travel the length of the tank and then down on top of the hairgrass & swords on the other side. Maybe optimistic but seems logical for a first go. What do you reckon?
 
Well, sorry, I don't trust any NO3 or PO4 test kit. I don't care how many times you measured. Can you tell me how many teaspoons or grams of powder you added to the tank? I strongly suggest you to abandon the technique of adding nutrient quantities based on measurements from a hobby grade test kit. The choice is yours, but Idi Amin "Dada" advises that this is bad Juju....very bad Juju....

Also, I've come to the conclusion that 3D backgrounds have a tendency to kill your flow/distribution. They are siliconed on and are a pain to remove, but well worth the effort in the long run.
The energy of the flow tends to dissipate quite rapidly along the long axis so this is not good unless the powerhead is extremely strong. A much better solution long term is to get a bigger filter, but of course that costs more. The powerhead is much more effective when mounted against the back wall. Strike 2 for the 3D background.

Cheers,
 
I don't estimate added NO3 & PO4 based on my NO3 test kit. I estimate them based on my calculations, which are correct (not being arrogant, it's my job to get calcs like this right). I was testing the accuracy of the test kit as much as anything else, which was certainly sufficient in this instance (although more exhaustive tests would be needed to actually estimate how accurate it is overall). The powders were measured with a balance, rather than teaspoons, but I would still say the concentrations added are only accurate to within 1ppm & .1ppm respectively.

Yeah on reflection I would have taken the background off when I bought the tank. 20/20 hindsight. Still, with a bit of trial and error hopefully I'll be able to eliminate any deadspots. Might be difficult in such a long thin tank and only one powerhead, but needs must.
 
I had BGA and after a blackout I was ok for a while, alas it started coming back, I have taken the timer off my CO2 ans have it running 24/7 at a slightly slowe rate....day by day the BGA started going away....its now gone completely

Think I will leave the timers off
 
Hi mfcphil

I had BGA in my low tech just after start up. This tank was being dosed with TPN+ at the time, as per manufacturers recommendations, which I now know was way off the mark (miles too low 🙁 )
I eventually upped the nitrates and it went away by itself in about 4 days.
Now dosing dry powders once a week in this tank, and all is well 😀
So might I suggest you put your timers back on and save your CO2. Total waste in the dark.
All you need to do is up your nitrates 😀
 
CeeJay said:
Hi mfcphil

I had BGA in my low tech just after start up. This tank was being dosed with TPN+ at the time, as per manufacturers recommendations, which I now know was way off the mark (miles too low 🙁 )
I eventually upped the nitrates and it went away by itself in about 4 days.
Now dosing dry powders once a week in this tank, and all is well 😀
So might I suggest you put your timers back on and save your CO2. Total waste in the dark.
All you need to do is up your nitrates 😀
Click to expand...


Been there done that....Nitrates are nearly treble what I started with, To be honest since I went 24/7 with the Co2 the tank has never looked better...I have 2 5kg f/e so I think I'll leave well alone for now.

Thanks though!!
 
Well the BGA is back yet again!

Tank 240l
Eheim pro3 filter
Co2 from 5kg Fire Ex going into my up atomizer through the 3ft spray bar along the back of the tank
2 hydor koralia water pumps (1 x size 1 & 1 x size 3)

Mix to 250ml water
KH2PO4 30g
KNO3 65g

Dosage 50ml Tuesday Thursday and Sunday after 50% water change

:crazy: :crazy: :crazy:

Oh and my crypts have all recently started to melt
 
Phil, it looks like you have a flow distribution issue. All the numbers look OK so I have to suspect that you have to play with your pump orientation. Any photos?

Cheers,
 
Hi Clive

This is an image before the new outbreak....I move the wood in case that has caused the flow problem

pics1.jpg

and this is the with the outbreak

pics3.jpg
 
I have a 3ft spray bar which goes acroos the back

this is one of the pumps

pics2.jpg


This is the other

pics4.jpg
 
Phil,
Have you tried moving that firs Koralia to the back wall? Both pumps should be on the back wall pointing straight ahead parallel to the flow of the sraybar. If that's 3 foot long then each pump should be place 1 foot in from the end walls and just under the bars. Imagine that the shape of the Koralias effluent is a cone. Having the pump pointing lengthwise influences the direction of flow from the spraybars such that the energy of the bars moves more to the left or right instead of straight forward. This reduces the efficiency of the jet streams from the bar. You want to amplify the jet streams from the spraybars, not divert or interfere with them.

It looks like you have stagnation points in the areas that the BGA has developed and in the areas where the melting crypts are. These a re classic areas of poor flow, i.e. at or near the substrate. I don't understand why everyone concocts these bizarre and exotic pump orientation configurations. It reminds me of soldiers taking up sniper position at the Battle of Stalingrad. Nature does not allow vacuums to develop. If you pump enough fluid in a single direction within a container the effluent will automatically find its way into areas of low pressure. So the idea is to maximize the flow rate in that single direction. If you distribute flow in opposite directions you cause incoherence, turbulence and destructive interference. There's no need to try and coerce the flow as if herding sheep mate. :shifty:

Cheers,
 
ok I've placed the other pump on the back wall...I will remove as much of the BGA as I can by hand and probably do a couple of extra 50% water changes over the nexk week, then see how we go from there!

Co2 is on 24/7 now and lights are 8 hours a day
 
Clive after taking your advice I made some more adjustments.

I replaced the nano Koralia and the Koralia 1 with 2 x Koralia number 2's, I also shortened my spray bar which I believe has increased the flow of Co2

TANK-5.jpg

TANK2.jpgTANK3.jpg
 
OK, looks better. I guess the proof is in the pudding. Can you see movement of the leaves on the lower crypts? Have things generally improved? It certainly looks like there are improvements.
It still looks like you have the Koralias pointed inwards and downwards as opposed to straight ahead. Is there a reason for this? Have you found that the flow/distribution works better than pointing them straight ahead?

Cheers,
 
Koralias are now pointed level and forwards 🙂

Crypts are flowing nicely thanks Clive
 
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