Raising Cory eggs & Shrimp safe fertiliser

[Biancah76]

Albino & Peppered Cory's spawning! Up til now it was just the peppered, but this morning I saw 1 of each with eggs between her fins. I also have 1 albino that hasn't grown at all since I bought them, and I have watched it eating, so I suspected the group weren't as healthy as the peppered.

I have been testing various forum methods to try and save some from my greedy Bristlenose, (mainly because I worry about her vegetarian gut, but my friend also said he would like a set) I have had some success, but I haven't yet pinned down which method it was that worked! I have tried 2 Types of breeder box (They either hatched and escaped, or were eaten by pleco because I have caught her climbing in & out), putting the adults in a separate tank (They seemed to stop spawning), and just covering the eggs in situ, with the divider from breeder & algae magnet, which allowed the eggs to hatch, but straight into a busy albeit peaceful community.

I woke up this morning to the biggest batch of eggs yet, so decided to run an experiment on which conditions they like best, because they scuppered my previous plan, by laying all of the eggs on the magnet and wrong side of the divider! After I collected them, 10mins later I looked again, and there were more!
I was just wondering if anyone could offer me their opinion on where to improve, because I have been collecting eggs now for a couple of months, and I have only grown 2 fry, there may be more hiding in both the community & nursery tank because I didn't actually see these ones until they reached at least 1cm long.
Listed methods photo's:

1)I have the ones on the divider in the floating breeder under main LED light, in the same corner they always lay eggs due to flow from canister with a net round it to monitor results/ give them a chance to mature a little before they join the rest.
2) I have a cookie jar, moss ball and baby bubbler in cupboard under tank for full darkness.
3)I put the algae magnet in the nursery biorb with no LED just natural light, plant's are suffering because I keep turning it off though (before anyone points it out, I do know how hideous biorb's can be but unfortunately the 80L I usually use as a quarantine/nursery sprung a small leak) it has a thriving well cycled bacteria colony, sponge filter and air stone and is maintaining the same water conditions as main tank, other than temperature as I turned the heater off (sitting at 21C, as someone on another forum pointed out the Cory fry like similar water/air temp for the first breath)

Any Recommendations on Fry/Shrimp safe fertilisers would be most welcome as well, I have a growing hair algae problem, I've been using shrimp safe root ball's & half dosing API Leafzone, with added CO2 but the Rotala (red orange and pink) are struggling to colour up and I fear succumbing to the algae.

 

[Biancah76]

Does anyone have any advice about preferred temperatures or a guess at age of juvenile from their Cory fry experience?

 

[ghyti]

Throw the plastic divider away and put the eggs on the bottom of your breeder box. Hang it in the tank to maintain temperature and put in an air line, either open line or air stone for circulation. When they hatch in about three days put in some of the green hair algae or other plant material, for the infusoria. Feed them micro-worms for the first month or so. No heater in cory tanks they like it cooler. You might want to try half and half rainwater or RO water and tap water for the breeder box.

 

[Biancah76]

Thank you, I think I might have already ruined the ones I left in community, they don't look as good as the others, I had to rub off a couple of fuzzy ones this morning although I think there is less today and there are slits in it. I've only just realised how tiny they are, they probably are escaping this box when not stuck down, but most of the ones in cookie jar have hatched and I now have tiny little eggs with tails swimming round! I have done as you suggested with food, Thanks

 

[Biancah76]

I was mistaken, all but three from the breeder box have gone while I was out today, I'm certain they've hatched and escaped through the side slits now I've seen how small these others are on hatching day. I had a net over the top to keep pleco out, so she hadn't eaten them. At least I gave them better odds than they had as eggs on glass, a couple may survive being eaten, there is loads of places to hide, or I wouldn't have the cute juveniles.
Do you think the little fry will be ok in 2L jar for the first month if I keep doing 50% daily changes? It's difficult to say for sure, because they are so fast but I think I've got at least 12 dancing around the bottom of jar when I open cupboard and let the light in.

Experiment findings so far: Seems the 2L jar (in dark cupboard @ 22C) hatched first, followed by the ones in main community (@24C with 8hrs of light), on the magnet I put in biorb (@22C with only natural light), there is half remaining one end unhatched that don't yet look degraded & half have hatched but I don't stand a chance of seeing them against the light sand yet.
Any idea when they start to colour up a bit?
Thank you Ghyti

Throw the plastic divider away and put the eggs on the bottom of your breeder box. Hang it in the tank to maintain temperature and put in an air line, either open line or air stone for circulation. When they hatch in about three days put in some of the green hair algae or other plant material, for the infusoria. Feed them micro-worms for the first month or so. No heater in cory tanks they like it cooler. You might want to try half and half rainwater or RO water and tap water for the breeder box.

 

[ghyti]

If the box has holes in it don't use it. As you have found out they will escape. A solid container is preferred. These work great https://kensfish.com/collections/traps-tank-dividers/products/marina-hang-on-breeding-box-medium
but any container should do, your 2 liter jar, a small fish bowl, a 1 gallon pickle jar, etc as long as you can keep the bottom clean. They will color up in a week or two, it doesn't take very long.

 

[AdoraBelle Dearheart]

I've jerry rigged some containers out of literal trash to contain eggs (well, cleaned out plastic tubs that were meant for the recycling bin, but came in handy as egg containers I could poke holes in for water exchange), but same difference!

One of my first attempts when I was surprised my bronze cories spawned in quarantine;

Personally I prefer something that attaches to the main parent tank so the fry are in the same temp and tank water as the parents, and from the moment they're laid until they hatch. As you've discovered, newly hatched cory fry are TINY, any I haven't seen a commercially sold breeder box small enough to contain them. Most sold are meant for livebearer fry, which are much much larger when born than an egg layer fry. Some people will rig small tanks or plastic containers without any gaps, can work well if you're religious about cleaning and water changes, and very careful, since fry are so delicate in those early weeks and super sensitive to high ammonia/nitrites/nitrates and any fluctuations in conditions.
I stole the idea from someone else to use the frame from a standard breeder box/net, and bought a pair of nude (so no nasty dyes) XL ladies tights, and stretch the foot part over the frame. Is a tight fit, but works wonderfully, and the netting is fine enough to contain the fry.

I use a plastic container like the first pic for the eggs so I can easily monitor for fungus, while it's held inside the net container using an algae magnet, in case of any escapees. Once they're mostly hatched and wriggling, I release them into the net. I like the net breeder personally since I only need to maintain the usual water changes on the main parent tank, so it's consistent parameters for the fry, and stick an airstone close by/underneath part of the net for good oxygenation and water movement. Within a few days I add some fine used sand from the established parent tank, since this is reported to harbour good bacteria that help the fry contend against potentially bad bacterial infections. I did have a wipeout of 40 odd fry on the last batch though when I hadn't changed the sand for a while, so personally I'd remove more of that during daily cleanings and replace with "fresh" sand from the parent tank every few days now.

I also use some alder cones and cherry shrimp as clean up crew and anti-fungus. As soon as I collect the eggs, I grab a few non-berried female cherry shrimp (only non-berried so there isn't the hassle of a lot of shrimplets in the fry container!) to be "nannies". They don't pose any threat to the healthy eggs or fry, but they do a fantastic job of cleaning off fungused eggs and preventing that fungus from spreading and ruining healthy eggs. They also help to clean up any uneaten food, as does the net breeder, since most passes through the net rather than gathering on the bottom and posing a hazard to the fry. Some live plant matter and an almond leaf to hide under completes the set up. A turkey baster makes a wonderful tool for moving small wrigglers and for cleaning containers/boxes/nets.

Once the fry are about a month old, I don't think the adults pose much threat to them, and most plecos probably wouldn't either, but that would have to be a personal judgement call about when or if you decide to release them into the parent tank or whether to move them to a different one. I moved my last batch of almost 100 fry to my pgymy colony tank, since I'd been having massive losses for two days, and I knew my pygmy cories thrive and breed in there without needing any real intervention. It's been established for years, well planted and filtered, and otos and pygmies pose no threat to fry. So if you want to keep spawning and saving as many possible, I'd try to set up a 15-20 nursery tank personally, with very fine sand, sponge filtration, lots of live plants etc, and get it really healthy and stable to be used as a grow out tank. I personally think mine are doing better having been in a stable parent tank for the first month, then having the space and established tank to roam in once moved to the established pygmy tank. No major losses since moving them, phew!

Everyone develops their own preferred methods and set ups, it's good to have an open mind and try things that work for you! It also gets easier with practice, and it's very common to have a lot of losses, especially with your first few batches, so don't beat yourself up if thins go wrong, and keep trying! If the adults spawned once, they'll spawn again. I managed to raise only 7-8 adults from my first batch, but still have close to 90 with my latest batch, and I've never deliberately spawned them. Just raised the odd batch when the parents happened to spawn! Good luck