CO2 injection & EI in planted arowana tank

[mordrake]

hi

just converted my tank to a low maintenance non-co2 setup in preparation for my to-be-purchased aro (hopefully).

as usual, the crypts n japonica has been melting since they were planted ard a week ago. not a worry. the rest of the plants like java ferns, windeluv, anubias are doing well.

question is, is it advisable to go back to co2 setup with EI for an aro planted tank? asking this cos starting to have bba forming on my bare wood, slight diatom and green dust on my tank walls.
this normal for newly converted co2 to non-co2 setups?

Tank Dimensions (LxWxH, specify units): 6 x 2 x 2.5 (FT)

Lighting Intensity(No of Watts) : 300W
Number and type of Lighting (FL/PL/MH) :2 x 150W MH (1 x 150W not on)
Age of light bulbs :less than 1 mth (10000K bulbs)
No. of hours your lights are on : 7

CO2 Injection Rate (bps) : na
Type of CO2 (DIY/Cylinder) : na
Method of Injection (e.g. Diffusor/Reactor) : na

Liquid fertilisers Used (Product name. E.g. Seachem Flourish) : Lushgro Aqua
Fertilization regime (Frequency and amount per dose) : 15-20ml per week

Other fertilisers (Product name. E.g. Root Monster) : JBL Aquabasis base fert

Other additives (Product name. E.g. Seachem Prime) : Prime

Type of Filter (overhead/internal/canister, Product name/model if possible) : 2 x eheim 2028, 1 x eden 212, 1 x eden 228
When was the filter last washed : 1 mth ago
Filter media used : eheim media, biohome n biohome plus, eheim blue sponge n white filter wool
When was the media last changed : last month
What was changed : white filter wool

Age of setup (i.e. since initial setup or last major re-do ) : initial setup 15months. convert to non-co2 - 10 days

Water change frequency : none since conversion to non-co2
Amount changed : na

Water surface movement (None/gentle/turbulent) : gentle
Circulation (None/gentle/turbulent) : slightly more than gentel

Tank Temperature : 27-28C

Chemical Properties (Fill what you can)
-------------------------------------
KH (dKH): 3
GH (dGH): -
pH : 6.8
NH4 (ppm): -
NO2 (ppm): -
NO3 (ppm): -
PO4 (ppm): -
Fe (ppm): -

stopped measuring NO3 n PO4 when i was on EI.

Bioload (Number and type of fish and plants)
------------------------------------------

fish
===
1) Cherry barbs X 6
2) Cardinal tetra X 90+
3) Oto X 2
4) Cory X 30++
5) adult discus 8
6) rams x 6
7) torpedo x 2
choc gouramis x 2
9) 6inch bristlenose x 1
10) rummies x 10
11) spotted headstander x 1

plants (60-70% tank footprint covered)
=====
anubias
java ferns
windeluv
crypt balansae
crypt wendtti - green
e. tennellus
b. japonica

Describe your problem :
----------------------
signs of bba on bare wood.
diatom and green dust on tank walls

[vinz]

I've run my planted arowana tank with 30ppm CO2 all the while and the fish was fine.

But I've observed that my arowana was slightly more sensitive to higher CO2 levels then it's tank mates, which are SAEs, tiger barbs, and otos. If I tweak the CO2 rate too high, it's the first to start skimming the surface. The other fishes do not seem to react at all.

It is not a extreme reaction like gasping or gulping air, but it changes it's swimming pattern such that it's only slightly below the water surface. This is the first sign that it's starting to feel uncomfortable breathing. All I need to do is tweak the CO2 back down and keep observing her until she stops the behaviour.

Precautions to take:
- Make sure you're around for most of the day to observe the fish whenever you change the CO2 levels.
- Make small gradual changes.
- Use a solenoid, so you don't have to worry about higher CO2 levels during the dark period.

Another thing to note, which not many people know. The arowana is a pretty primitive fish and their organs are not as advanced as more modern fishes. One really important organ of note is the liver. The arowana's liver cannot handle fish medication at the usual dosage levels. Shops normally half the dosage, if it's necessary to dose. Otherwise, use medication specific bottled for Arowanas. Most are ordinary fish medication, but I suspect the concentration or the recommended dosage have been reduced.

[mordrake]

thanks for the tips Vincent
never had to medicate the tank only for white spots when my discus was intro from bare tanks (30C) to the planted (27C) in Jan'05.
within 2 weeks, all was fine... no disease outbreak since then...

hope my tank is stable enough for the aro.

another thing, how does aros react to fert dosing? i tend to dry dose most of the time

[mordrake]

okie, here's a pic of the rescaped tank after 2 weeks.
signs of bba on wood n now tank walls too. green dust very little ...

don't want to go back to co2 high tech setup...
any advise to fight the bba for this low tech setup?

all info regarding the tank is in 1st post of this thread, except that i added a 6inch aro last night

thanks

[vinz]

A 6 inch arowana is probably going to decimate the small fish population in that tank. At that size, it's still pretty agile. Plus you don't have a lot of dense planting for them to hide in.

I can see the fella in the top right corner of the tank... which species is it?

The arowana might get hurt if it tries to dash into those wood to catch the fishes.

Is the tank covered? Aros are jumpers.

When it gets big... probably will reach 12 inches in 6 months and 18 inches in about 12 months... it's going to be a massive ammonia/nitrite/nitrate producer. That means algae is highly likely. You're probably going to have to go high CO2 and EI for that reason. Skip the NO3. Just lots of PO4, traces, and equilibrium.

Put in one stand of fast growing stem plant like a Hygrophila to handle the NO3. The rest can be easy rosette plants like Java ferns, Echinodoruses, Crypts (they'll love the NO3). APP and Hydrocolyte will do well too with higher NO3.

I'm not sure how to clear BBA in a low-co2 tank. But a low-maintenance tank need not mean no CO2. Make sure CO2 is well distributed. Personally, in a large tank like this, I've found that using a rainbar across the back of the tank, pointing forward, for the CO2 enriched water outlet (from filter) works well.

Man, you make me envious... it'll be a few years before I can start another planted arowana tank.

[mordrake]

A 6 inch arowana is probably going to decimate the small fish population in that tank. At that size, it's still pretty agile. Plus you don't have a lot of dense planting for them to hide in.

the aro is getting along fine with all the fishes at the moment. the discus and rams went to sound the aro out in packs when 1st introduced. now all the fishes are back to their own routine with the aro keeping to the top half of the tank.

I can see the fella in the top right corner of the tank... which species is it?

DFI Crossback Golden

The arowana might get hurt if it tries to dash into those wood to catch the fishes.

hope the japonica n crypts settles fast n provide some buffer

Is the tank covered? Aros are jumpers.

yep, the tank is covered

When it gets big... probably will reach 12 inches in 6 months and 18 inches in about 12 months... it's going to be a massive ammonia/nitrite/nitrate producer. That means algae is highly likely. You're probably going to have to go high CO2 and EI for that reason. Skip the NO3. Just lots of PO4, traces, and equilibrium.

since it's only in for a couple of days, safe to inject co2? scared not stable yet

Put in one stand of fast growing stem plant like a Hygrophila to handle the NO3. The rest can be easy rosette plants like Java ferns, Echinodoruses, Crypts (they'll love the NO3). APP and Hydrocolyte will do well too with higher NO3.


I'm not sure how to clear BBA in a low-co2 tank. But a low-maintenance tank need not mean no CO2. Make sure CO2 is well distributed. Personally, in a large tank like this, I've found that using a rainbar across the back of the tank, pointing forward, for the CO2 enriched water outlet (from filter) works well.

yep, i have a rainbar across the back bottom of the tank... ard 4ft in length. setup this way when the tank was co2 high tech.

Man, you make me envious... it'll be a few years before I can start another planted arowana tank.

no need what so long la, all that's missing is the aro right?

[vinz]

Yes, you can start CO2, but take it slow and remember the KH. Be around to observe.

I asked the guys at Sam's Pets Showroom in Joo Chiat before... the have to replenish the tetra school very once in a while. You won't see a feeding frenzy. The fishes will just disappear a few at a time. The more you have, the easier for it to catch.

Thing is I might move hosue soon, so I don't want to deal with the logistics of moving and temporary storage of a large fish.

[bclee]

BBA will slowly die out by itself in non-CO2 tank. Just keep your plants healthy. Pick at them when you see them (not so difficult in non-CO2 as they grow much slower). Soon, they will slowly go away.

I would say planting more will help, especially with an aro in it. It will help to deal with the NH3/NH4 that is the root cause of most algae.

Don't fertilise unless absolutely necessary.

The biggest maintenance in CO2 enrich tank compared to a non-CO2 tank is WATER CHANGE. With CO2, you need to dose ferts, and then you will need water change.

You can sometimes go on for months without water change in non-CO2 tank.

BC

[mordrake]

hmmm.. maybe i'll get some hornwort or floating plants to tackle the NH3/NH4 ..

will eventually have to move the discus out too...

[celticfish]

Yes, you can start CO2, but take it slow and remember the KH. Be around to observe.

I asked the guys at Sam's Pets Showroom in Joo Chiat before... the have to replenish the tetra school very once in a while. You won't see a feeding frenzy. The fishes will just disappear a few at a time. The more you have, the easier for it to catch.

Thing is I might move hosue soon, so I don't want to deal with the logistics of moving and temporary storage of a large fish.

vinz,
i second that!
i use to have a green arowana.
at one time i tried to breed some convict cichilds - bought four and two died.
then i decided they should do their part by being fodder for the aro...
however i did give them a chance buy placing some rocks for them to hide in the corner.
man they bred like rabbits!! go figure... benny remember what you said about yorky?

they would have one spawn growing to about an inche and they start another.
i left them in place as i did not have a spare tank.
the parents survived but the school of fry got lesser and lesser.
one day i came home an observed the aro gliding across the tank.
as it swam pass the school it just tilted its head to one side and swollowed a fry.
the whole school just carried on not knowing one of their brethen had become a meal...

[PeterGwee]

I would say planting more will help, especially with an aro in it. It will help to deal with the NH3/NH4 that is the root cause of most algae.

Ditto. Large plant mass rather than a bunch of fast growing stem plants will help more. Add some floating plants like duckweeds (weed!!!) to cover 20-30% of the surface. (They get atmospheric CO2 and grow very fast!)

Nutrient dosing isn't really the issue but a potential for buildup to toxic levels due to stopping of water changes to stablize the low CO2 is the main issue. Rubisco stuff....

Read more into the non-CO2 article.

Regards
Peter Gwee

[vinz]

BBA will slowly die out by itself in non-CO2 tank. Just keep your plants healthy. Pick at them when you see them (not so difficult in non-CO2 as they grow much slower). Soon, they will slowly go away.

I would say planting more will help, especially with an aro in it. It will help to deal with the NH3/NH4 that is the root cause of most algae.

Don't fertilise unless absolutely necessary.

The biggest maintenance in CO2 enrich tank compared to a non-CO2 tank is WATER CHANGE. With CO2, you need to dose ferts, and then you will need water change.

You can sometimes go on for months without water change in non-CO2 tank.

BC

One key of low/no-CO2 tank is low bioload. A single adult arowana in a 6ft tank is not low bioload... especially if the arowana is fed with live food or unprocessed food (e.g. market prawns). NH3/NH4/NO3 is going to be a major problem. Enough plants in a low/no CO2 tank to handle that = no space for arowana to swim. No/infrequent water change is not an option either.

Floating plants might help.

[vinz]

Just an example: My arowana planted tank was a high-light, CO2-enriched, fertilised tank. Even when the arowana was only 12 inches, the NO3 levels were at 20 to 40 ppm before a water change.

[PeterGwee]

Vinz, did you calibrate the test kit using standard stock solutions w/DI water.

Regards
Peter Gwee

[mordrake]

Ditto. Large plant mass rather than a bunch of fast growing stem plants will help more. Add some floating plants like duckweeds (weed!!!) to cover 20-30% of the surface. (They get atmospheric CO2 and grow very fast!)

Nutrient dosing isn't really the issue but a potential for buildup to toxic levels due to stopping of water changes to stablize the low CO2 is the main issue. Rubisco stuff....

Read more into the non-CO2 article.

Regards
Peter Gwee

that's what i intend to do.. pack more plants in. think i'll get more crypts..
i'll give the duckweeds a miss though... will be a potential nightmare.

i also intend to do waterchanges when nutrient levels buildup to uncomfortable levels to keep things in check. just have to test once in a while.
as long as i do not need to trim, dose, inject co2 and still have a healthy tank, i'm very happy.

[vinz]

Vinz, did you calibrate the test kit using standard stock solutions w/DI water.

Regards
Peter Gwee

Yes, with stock solutions, but not with DI/water, but with tap water. Tested the tap water without KNO3 too, as a reference.

Test results for my other tanks made sense.

Other brand test kits gave similar results.

[joe]

non-CO2 method encourages the usage of aerial plants since they have a huge advantage over submersed plants due to abundance of CO2 in the air ... frogbits are fine la, but not duckweeds

[vinz]

Melvin, I just remembered something...

Bright lights are no good for the colouration of the x-back arowana. Bascially, it causes the fish to produce their equivalent of melanin, which is brown and will cover the gold and the fish will not be a cross back anymore. The fish is being tanned.

In red arowanas, the bright lights are good because their melanin equivalent is red... which is the desired colour.

In other words, you would want the x-back to remain "fair", and the red to "tan".

The good news is, it's not permanent. Once the fish is subject to a period without bright lights, it will become "fair" again.

That's why reds are considered better for the planted tank as the colour contrasts well against the green and the bright encourages the colouration.

I know of a case of a red that is always swimming in anti-clockwise along the walls. It ended up nicely coloured on the left side of it's body and paler on the right side.

In practice, people who keep x-backs tend to keep them in dark tanks with very little light. Lights are turned on only for viewing and left off otherwise. Whereas, for a red, some people keep the lights on 24/7 (not a practice that I condone because I believe it will disrupt their bio-clock and cause stress). A typical low-light planted tank is still considered too bright for the colouration of a x-back.

[mordrake]

Vince, very useful info.
i'm using 10000k bulbs that are pretty blue to the eye.
the intensity is not as strong as those 6500k bulbs. shouldn't be a problem right? which the tank top covered by green netting, the intensity is further reduced. may get glass cover later on though

as backup, i can just on the centre pendant and leave the other 2 off...
150W for this tank....hmmm.... feasible?

[vinz]

Then your side plants will not get enough light. Overall your plants may not grow as fast as necessary to handle the N products.

Frankly, I do not know how low is low enough. Typical x-back keepers keep their fishes in un-lit tanks except for viewing. Most tanks only have 1 or 2 daylight FL tubes.

Don't get glass covers. They are heavy and breakable. They also restrict air circulation, thus restricting CO2 supply to your floating plants, and retains heat.

I used stainless steel mesh covers with a 2 inch grid (i.e. each "square" is 2" by 2"). I used my fan clamps to wedge them in place, but you can fashion some kind of fastener on the bracings to hold it down. That grid may be too big for your arowana now, so you might want to overlay it with another plastic mesh until it gets too big to fit thru the grid.

From my observation, my arowana is less likely to try jumping if it can see obstacles... i.e. the mesh. Glass on the other hand, can be quite "invisible" to the arowana. If it really wants to leave the tank, it will try to jump through any openign it thinks it can fit thru.

The arowana might try jumping blind in the dark. I've noticed my arowana will try to jump blind in the dark if it does not like the water. Turning on a small light source (tank or room) usually stops it from jumping, but it'll still display agitated behaviour. I'm assuming that it does not jump anymore because it can see the mesh.