Corydorus.Sterbai in Discus tank

[Biscuit]

Hi

I have a 260 litre tank containing 6 young Adult F1 Discus. The Discus can be a little timid. I have had the Discus for about 1 year. The tank has been cycled for 18 months. Spec as follows:
Lightly planted 260 litre with sand substrate, 2x external filters, 28.5C, Ammonia 0ppm, Nitrite 0ppm, Nitrate 10-20ppm, pH 7.2. 50% water changes 4 times per week using aged & pre-heated HMA water. No issues apart from some green algae on substrate. Fed 3 times per day mainly with Beefheart, also frozen bloodworm & NLS pellets. Main T5 lighting 3 hours per day, remaining time blue & red LED lighting. Lights off 11 hours. This is a show tank & although the Discus spawn, I do not wish to breed.

I would like to consider Sterbai as I understand that they would go well with the Discus. Hoping that is correct, would the Sterbai appreciate some little hiding places & if so, what would you recommend?

The Discus will occasionally bolt, sometimes when feeding. What effect would this have on the Sterbai?

Finally, assuming Sterbai are suitable, what is the best source?

Thanks.

[exasperatus2002]

I had wood cats (Trachelyichthys exilis) with my discus. Having some other fish, which sterbai would be a good choice, helps them feel more secure. With no others around, some discus feel as if they need to constantly look over their proverbial shoulder. My heckels were like that. I also had a school of cardinal tetras and threadfin rainbows.

[exasperatus2002]

I had wood cats (Trachelyichthys exilis) with my discus. Having some other fish, which sterbai would be a good choice, helps them feel more secure. With no others around, some discus feel as if they need to constantly look over their proverbial shoulder. My heckels were like that. I also had a school of cardinal tetras and threadfin rainbows.

My tank was a planted tank, mostly Jungle val., Crypts and driftwood at a PH of 6.5 and 82* F.
That was back before I found planet catfish and found that I was keeping the wood cats to warm.

[Coryman]

C. sterbai, would be a good choice regarding temperature, but the one problem that can occur is with the diet. Basically the high protein foods made for Discus are far too protein rich for Corys, and will eventually cause problems. The only way to combat this is to have a good supply of live foods like Tubifex, blood worm and especially Daphnia.

Ian

[Biscuit]

Thank you all for your replies.

Ian, you mention foods, but I am concerned about feeding live foods to my Discus. Perhaps I could offer the Corys something like Algae wafers?

[apistomaster]

I've raised Discus off and on since 1969.
I have kept Corydoras sterbai with Discus in display only tanks without any problems.
I feed Discus earth worm sticks, Tetra Color Granules, frozen blood worms and sometimes live black worms although live black worms are not essential and the C. sterbai often spawned.
Discus actually do not require a diet that is unusually high in protein.

[Biscuit]

When I try to feed my Discus pellets, they look at me in disgust!

With Sterbai in the Discus tank, would the little guys appreciate some sort of hiding places? perhaps some sort of breeding tubes to help them to feel safe?

I am looking at getting the Sterbai from Rare Aquatics. Is this a good source? The Sterbai would be wild caught. I would quarantine them for 6 weeks. Is that enough?

[Mol_PMB]

I would recommend Rare Aquatics - I've always had great healthy fish and excellent service from them.


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[apistomaster]

When I try to feed my Discus pellets, they look at me in disgust!

With Sterbai in the Discus tank, would the little guys appreciate some sort of hiding places? perhaps some sort of breeding tubes to help them to feel safe?

I am looking at getting the Sterbai from Rare Aquatics. Is this a good source? The Sterbai would be wild caught. I would quarantine them for 6 weeks. Is that enough?

If your discus are being choosy about food try this; Feed new foods along with one they already eat then gradually decrease the familiar while increasing the new.
I've never had any discus not accept frozen blood worms so I'd try those then begin introducing any new items to their diet.

I have always found 4 weeks of quarantine to be more than sufficient.
Some broad leaved Echinodoras or Cryptocoryne are good warm water plants. You may find that providing overhanging ledge and shallow cave plus your plants to be sufficient cover.

[Biscuit]

I would recommend Rare Aquatics - I've always had great healthy fish and excellent service from them.

Thanks.

[Biscuit]

If your discus are being choosy about food try this; Feed new foods along with one they already eat then gradually decrease the familiar while increasing the new.
I've never had any discus not accept frozen blood worms so I'd try those then begin introducing any new items to their diet.

I have always found 4 weeks of quarantine to be more than sufficient.
Some broad leaved Echinodoras or Cryptocoryne are good warm water plants. You may find that providing overhanging ledge and shallow cave plus your plants to be sufficient cover.

Thanks, I feed them frozen bloodworm for breakfast every other day. This alternates with NLS pellets. I was thinking of feeding NLS algae wafer specifically for the Sterbai. I already have a few Echinodoras Bleheri, but plants don't do well with me.

[apistomaster]

I always feed discus frozen blood worms once everyday.
I also recommend feeding them three times a day using a variety of foods.
Maybe once in the morning, when you come home from work and once more before lights out.

Echinodorus are heavy feeders. Assuming you have enough of the right lighting, the best thing you can do is put Echinodorus in pots. I use clear plastic containers and no holes.
If the pots have holes in them then the roots will intrude into the surrounding substrate.
I mostly use clear plastic juice container bottoms. I cut them to about 3-1/2 to 4 inches high.
Use a good plant substrate and substrate time release fertilizer. It makes a world of difference. I conceal the pots by burying them in the surrounding substrate.
When plants are potted thusly then they have exclusive access to all the fertilizer. The root systems are contained so they are never disturbed during any gravel vacuuming and one can relocate the plants without causing any transplant shock.
I've grown huge Echinodorus bleheri and other large Echinodorus species in relatively small containers. The pots often become root bound but it doesn't seem to hinder growth of well fertilized plants. I never use fertilizers in the water column. What's the point of flushing them from the tank as one will do if you are making the large and frequent water changes discus need to thrive? Might as well be pouring expensive fertilizers down the drain. Echinodorus and Cryptocoryne don't take in fertilizers from the water anyway.

[dw1305]

Hi all,

Echinodorus and Cryptocoryne don't take in fertilizers from the water anyway.

I like Apistomaster's methods, but that isn't actually true, even alleged "heavy root feeders" will get a lot of their nutrients (as ions) through their leaves.

Plants can only take up nutrients as ions, so even for root uptake the nutrients have to be in solution.

cheers Darrel

[apistomaster]

As I'm sure Darrel is aware, most Echinodorus and Cryptocoryne are bog plants which grow emersed better than submersed. That is how the two genera are mass produced by commercial plant nurseries and how most grow in the wild throughout much of the year. Emersed Echinodorus and Cryptocoryne do not normally depend upon extraction of nutrient ions via their leaves except for CO2.
In their immersed habit their leaves do have some ability to directly extract nutrient ions but substrate fertilized potted specimens will outgrow a soly water fertilized ones in controlled conditions every time.
It is still far cheaper and efficient to use substrate fertilizer in a planted discus tank which is given large and frequent water changes. Discus do not thrive without large and frequent water changes. Most Corydoras also prefer similar water quality.
If one doesn't mind the added attention and expense of using liquid fertilizers one will be largely flushing down the drain, by all means, go for it.

[Biscuit]

Thanks for the advice regarding the pots.

I currently have the plants stuck in the sand substrate with only JBL root balls for fertiliser. I would not want to use fertiliser in the water column. I have previously been thinking about some sort of pot system & am interested in the statement that the roots may be fully contained on the pots. I'm a little concerned about the pot lids showing above the substrate in case the fish damage themselves during the occasional bolting. I had also been considering either some glass "sundae" dishes (maybe even ash trays) or possible some sort of amphibian feeding dishes as a pot. Main tank lighting is only 3 hours per day due to the green algae issue.

Obtaining Corys from Rare Aquatics seems to be a no-go at the moment as they only use APC couriers which will take 3 days to reach me. I may however consider travelling to get them personally. During the 4-6 week quarantine period, should I also consider the "sacrificial lamb" procedure or is this only when introducing additional Discus & not necessary with Cory?

My suggested quantity of Cory would be 6. Is this enough?

[Coryman]

Algae wafers are not suitable for Corys, they are omnivores and require a variety of small foods.

Feeding beef heart to the Discus is fine but like algae not good for Corys.

Ian

[apistomaster]

I agree with coryman.
I have raised thousands of discus for sale and raised them on homemade beef heart blends but I quit using beef heart. I found I could get excellent results using earth worm sticks for even discus fry plus live Artemia nauplii. Later on I feed discus earth worm sticks, frozen blood worms, Tetra Color Granules and some live black worms.
I have had good results feeding and breeding Corydoras, Hypancistrus and Peckoltia species on the same foods as I used for discus.

It seems to me like you are more concerned about potential injury to panicked fish hitting edges of buried makeshift pots than is warranted. I've used these types of containers for potting plants for more than 4 decades and never had any problems. Inevitably the edge of buried pots become expose by about 1/4 inch from fish and maintenance activities. That is why I chose clear materials. Suitably sized manufactured clear glass containers work just as well as cut plastic juice bottles so use the glass containers if you can find them.

I would allow for some mortality when buying young 2-1/2" range discus. I would recommend buying at least 2 more than I want as full grown. There is often a runt and always one lowest in the pecking order which often falls far behind the others. Buying a few extras of any species you plan to keep and breed is never a bad idea.

Corydoras sterbai can be problematic fish to ship. When they are stressed and in confinement they often exude a toxic secretion. This can induce fatalities very fast. I raised a thousand back when they were retailing for about $15 each but found that shipping problems were too severe to continue to bother with them. I tip my hat to anyone who has perfected the art of shipping C. sterbai without losses.

[Biscuit]

when buying young 2-1/2" range discus

Did you mean young Discus or Cory? Maybe a mis-type?

I take note about the pots, although my Discus do manage to scratch themselves on the heater holding clips & the filter intake strainers. I suppose though that they are generally aiming upwards when that happens. I may try to find some shallow glass bowls.

I have heard about the toxins from Cory. I was considering travelling to fetch the Cory rather than having them posted. is there a danger of the Cory releasing toxin once settled in the Discus tank?

[Corycory]

Corydoras sterbai can be problematic fish to ship. When they are stressed and in confinement they often exude a toxic secretion. This can induce fatalities very fast. I raised a thousand back when they were retailing for about $15 each but found that shipping problems were too severe to continue to bother with them. I tip my hat to anyone who has perfected the art of shipping C. sterbai without losses.

When I got my sterbai they only travelled in a bag from the shop to my place which took an hour the most and they had signs of poisoning already.
If I ever buy sterbai again(though mine survived) I'd ask them to be placed each in a separate bag of water.

[apistomaster]

I was referring to small discus when I recommended buying a couple extras.
I could generalize that to Corydoras sterbai or most other peaceful fish if you want a minimum number of them to survive regardless of their size or age.
Especially when buying fish online but anytime one buys perishable livestock some losses should be anticipated. These are my personal opinions. Everyone is free to make their own decisions.

I want to relate an experience I had which was similar to Corycory's.
Once I had a shipment of Corydoras sterbai subadults packaged for shipment.
I did not know at that time that I had to go to the main UPS facility to ship fish so I returned home within 1-1/2 hours to regroup. I opened up the package and found them already dead or dying. I was only able to save 5 out of 12.
This phenomenon is better known among the reef fish hobby with regard to shipping puffers and cowfish.
I was aware of the problem before I bagged them so I did deliberately stress them a bit and made several changes of fresh bag water over about one hour plus added the now discontinued Jungle Bag Buddies fish tranquilizer that I had used to successfully ship hundreds of Leopard Frog Plecos and Hypancistrus sp L333. Individually bagging C. sterbai in more water than one might normally use for a similarly sized species may be the best way to reduce shipping losses.
I had shipped dozens of bags containing only 4 oz of water and 6 Corydoras hastatus without any losses. The rapidity of self-intoxication of bagged Corydoras sterbai almost has to be seen to be believed.

[Biscuit]

I was referring to small discus when I recommended buying a couple extras.

Thanks, but I already have my Discus. I bought them as sub-adults & collected them myself.

Point taken about bagging the Cory separately.

[dw1305]

Hi all,

As I'm sure Darrel is aware, most Echinodorus and Cryptocoryne are bog plants which grow emersed better than submersed. That is how the two genera are mass produced by commercial plant nurseries and how most grow in the wild throughout much of the year. Emersed Echinodorus and Cryptocoryne do not normally depend upon extraction of nutrient ions via their leaves except for CO2. In their immersed habit their leaves do have some ability to directly extract nutrient ions but substrate fertilized potted specimens will outgrow a soly water fertilized ones in controlled conditions every time. It is still far cheaper and efficient to use substrate fertilizer in a planted discus tank which is given large and frequent water changes.

No I'm not disagreeing with any of this, and I think potting the plants in a nutritious substrate is a good idea, particularly for Discus.

Most aquarium plants will grow better emersed than submerged, partially because of access to aerial levels of CO2. If you are Tropica etc. it makes much more sense (for economic reasons) to produce plants that can survive under water, rather than strictly aquatic ones (like Ceratophyllum, Potamogeton spp. etc), even though aquatic ones may be more suitable in many cases for aquarium use. But, even strictly terrestrial plants (like Tomatoes) can take in their nutrient requirement through their leaves. This from Kannan & Charnel (1986) "Foliar absorption and transport of inorganic nutrients" Critical Reviews in Plant Sciences 4:4

All plant cells — those of roots, leaves, or other parts — are capable of absorbing water and solutes as well as gaseous substances. This trait, derived by terrestrial plants during evolution from their ancestral aquatic habitat, is exploited in many agronomic practices. The pathway of entry of nutrients supplied to the leaf involves penetration of cuticular membranes enveloping it, absorption by the cells within, and transport away from the leaf.......

I'm not a great fan of Beef heart either, and I don't see any problem with using cut plastic drink bottles as your pots, they are both cheap and effective.

cheers Darrel

[apistomaster]

I've heard that "foliar feeding" of Cannabis is used by many growers during the vegetative growth phase.

[dw1305]

Hi all,

that "foliar feeding" of Cannabis is used by many growers during the vegetative growth phase

I wouldn't be at all surprised, we used to use it for Tomatoes. I almost typed "foliar feed & cannabis" into Google then, but I'm at work, so maybe not the best idea.

cheers Darrel

[aquariumhobbyist]

I agree with coryman.
Corydoras sterbai can be problematic fish to ship. When they are stressed and in confinement they often exude a toxic secretion. This can induce fatalities very fast. I raised a thousand back when they were retailing for about $15 each but found that shipping problems were too severe to continue to bother with them. I tip my hat to anyone who has perfected the art of shipping C. sterbai without losses.

Not that this is a 100% perfected method but I would say it gives better results than anything so far: collect all C. sterbai that need to be shipped and place into a 10 gal bucket of aquarium water (needs to be clean obviously, free of chemicals and so on). Place in a more dim environment (to reduce stress from light) and over the next 25-30 minutes, give the bucket a good kick that is enough to get the toxin release reflex from the fish but not too much to increase stress levels unnecessarily (like you would if you unintentionally bumped into the bucket with the side of your foot while trying to pass by it), say about once every 5 minutes. Have another 10 Gal bucket with aquarium water ready and transfer the fish here, repeat. The fish should have exhausted most of their toxins in their toxin glands now. Bag each fish (with fresh water from the aquarium) individually and ship.

The problem with just shipping individually is that any bump or stress creating factor during shipping causes the fish to release their toxins, thereby poisoning themselves.

[Biscuit]

That's interesting, thanks.

It sounds also to be worth considering that process when transferring Cory from quarantine to the main tank.

(I've still not found any Cory for sale though)