Advice needed

[KerriM]

Good Morning,

This is my first post on this forum . My clownfish began to lay eggs in August and having done a lot of reading I decide to have a go at raising them. I am now attempt number 2. I have set up a separate tank which is blacked out with paper (it is 90 litres so have been filling to about half full to match the 10 gallons recommended) and I have a rotifer bucket going. On attempt number 1 we managed to collect a large number of the fry (they lay on a rock that is too big to move the eggs). They looked fine for the first day so however on the second day they started to look energyless and swimming vertical. They began to drop off until eventually the last of the stragglers perished at the end of day 4. I figured this was a rotifer density problem so decided to co-culture in the fry tank for attempt number two.

However the same thing appears to have happened. They looked great on day one and seemed to be darting and have full bellies but after this they started to swim slightly vertical again and I think I have lost a number (it's hard to tell due to the green tint of the water). I'm now on day three and the remaining ones seem quite lively and darting around when I top up the rotifers.

Do you think this is a rotifer density problem? Also how often would you recommend doing and starting water changes. Some seem to being straight away others wait until a couple of days?

Many thanks for your help,

Kerri

[shorty]

I have VERY LITTLE experience so far, so take this for what it's worth. Hopefully someone else with actual experience will chime in. I'm on my 2nd batch (which is going ... okay... so far) - I have 50 or so left just starting to hit meta today/this weekend. I only have 1 left from my first batch.

I lost all my first batch after 24 hours minus the one previously mentioned. I believe my problem was that I wasn't providing enough oxygen... dense rotifer population + 100 plus larvae in a small tank seems to require a decent amount of oxygen input. Just one thing to consider.

[Amie]

two questions: What kind of light are you providing to the tank? What kind of air supply do you have running?

[Luis A M]

Hi Kerri,be welcome!
It´s hard to tell what your problem is,but let´s elaborate around it.
First,your eggs hatch and 2nd they don´t die in the 1st night.This is something
Why you mention rots density?suspecting it is too low or too high?
You co-culture a batch when many rots remain uneaten and you add algae to feed the rots and they multiply in the larval tank.This doesn´t happen when you have many larvae;all the rots are eaten and you must keep adding more.
Keep the circulation closed for the 1st 5 days,if your NH3 badge keeps yellow,and start dripping new water after that.
Ending,three magic bullets that could solve your problem;you can try one,two or all of them,make your own experiments.
Hatch in Cl sterilized new water.
SG at 1.010
Dose antibiotics in the hatching night.
Good luck!

[KerriM]

Hi again. Thank you all for your advice. This story has taken an upturn - there are about forty fry still swimming around and day seven is just beginning .

To take each post in turn:

Shorty - I think you make a good point about the oxygen levels. I'm going to look at maybe adding another airline for the next try. I currently only have one in there.

Amie - I believe the light is two 15 watt interpret lights one day light and one moonlight. The aren't close to it though as the tank is full. They arent/weren't swimming in circles or stuck at the bottom although it is possible it was too dim perhaps. I have one flexible airline running.

Luis - thank you for the welcome. Thank you for the tips these are definitely things I am going to look at for next time. I was thinking that the rotifer density might be too low but they did seem to have silver bellies - I think one mistake I made was only having my rotifer bucket going for three days before - it probably didn't have time for the numbers to get up. I didn't realise that about co-culturing - do you still advise tinting the tank with phyto? Does that mean you don't do water changes until day five. How should I set up a drip system? At the moment I am currently having to gently jug the water in and out. Would it be a problem to have the SG so much lower than my parent tank?

Thanks again everyone for the advice

[shorty]

Kerri,
You may already be thinking along these lines, but I personally wouldn't change everything at once. I think you've been given good tips (and I'm taking notes myself! ). But I think these are applicable if you continue to have problems. I personally would pick what I assume is the biggest offender and then change that one thing with each batch to see what works for me. The problem with any shotgun approach is that even though it may work, you may be creating significantly more work for yourself than necessary in the long run for all future batches.

As far as the drip question, I have a shelf above my tanks that I can put a top-off water and/or broodstock water buckets. I then just use airlines and plastic air valves creating a syphon to get the correct drip rate down to the fry tank. The drip method of water should definitely help buffer many water parameter differences and be more gentile on your fry.

Another thing with the air - you mention air lines. Are you using air stones? More bubbles (via the stone) will help diffuse the oxygen into the water and may help the efficiency of each air pump.
good luck!

[Amie]

If you keep the tank lightly tinted with phyto, and let the rotifers mass produce in the tank with the fry, you will be able to keep your ammonia levels down dramatically. I usually start my fry tanks 1/2 full (10 gallon tanks), and drip a fresh 1/2 gallon of SW into the tank every day in order to reduce the nitrates. I only syphon out dead bodies for the first 5+ days. I don't do any water changes until after they have gone through meta. The less they are disturbed, the better.

I asked about the light because I leave a small light on all the time, I never leave them in the dark. that way they can eat at night. I used to have a lot of deaths the first 24 hours until i started leaving a light on all the time.

[onsan]

a quick fix for ammonia is to add a drop of hydrogen peroxide.
NH4 + 5H2O2 -> NO3 + 7H2O
I use this whenever I noticed poor fish motility in brood tanks, a very quick fix.
We used to use it in transporting fish fry and prawn PL's from hatchery to growout on the farms I worked at.

[Amie]

a quick fix for ammonia is to add a drop of hydrogen peroxide.
NH4 + 5H2O2 -> NO3 + 7H2O
I use this whenever I noticed poor fish motility in brood tanks, a very quick fix.
We used to use it in transporting fish fry and prawn PL's from hatchery to growout on the farms I worked at.

Nice tip...1 drop for how many gallons?

[shorty]

That is a good tip. How does that compare with products like 'amquel', other than being a lot cheaper. Doesn't amquel detoxify NH3, NO2, and NO3 somehow?
Speaking of which, isn't the toxic form of ammonia NH3, not NH4? I don't know chemistry well enough, and wouldn't be able to even start to check that conversion if I wanted to.

[onsan]

ok, the drop thing was a little blasé, but it is a pretty safe (and cheap) chemical.

really, this should be done on molar concentrations, but as it is safe enough and to keep it simple... we'll just stick with ppm.

For every 1 ppm of NH4 you need 5 ppm of H2O2 to completely oxidise it to NO3.
The formula you use to calculate it is a simple one, V1 = C2V2/C1
V1 = Volume of H2O2 required.
C2 = Concentration of H2O2 needed to neutralise the ammonia (5:1 as above)
V2 = Volume of your tank/system.
C1 = Concentration of H2O2 in the bottle.

So, if you have 5ppm NH4, you will need 25ppm of H2O2 to neutralise it.
Say you have a 20L tank.
Say your pharmaceutical/food grade (not cosmetic grade) H2O2 is 3%. (convert % to ppm by multiplying by 10,000, so 3% = 30,000ppm)

V1 = (unknown in L)
C2 = 25ppm
V2 = 20L
C1 = 30,000ppm

V1 = 25x20/30,000
V1 = 0.016L (note! that if V2 was in L, V1 will be too! times the answer by 1,000 to convert to mL)
V1 = 16mL

So, to neutralise 5ppm of NH4 in a 25L tank, you need at least 16mL of 3% H2O2.

I say at least because NH4 is not the only ion or organic matter that will demand (use/deplete) H2O2; bacteria, algae, chlorine, iron...

If all that is too complicated, add a mL at a time till no ammonia is present, it is a rapid reaction, mix the water, test, repeat till gone.

Amquel is sodium formaldehyde bisulphite, it works by a different mechanism, I'm not sure but I think it reacts as such;
2 CH3NaO4S + 2 NH4 = 2 CH3O3SNH4 + 2 Na + O2
At the pH's we typically deal with it's ammonium NH4, however the peroxide still works, as below;
2 NH3 + 9 H2O2 = 2 NO3 + 12 H2O (so you need 4.5 mol of H2O2 to do the job).

I don't know how bioavailable the bound NH4 (or NO2/NO3) will be, my prefererance is to use the peroxide as my aim is to simply rectify the ammonia and allow the biological filtration to deal with the nitrate.

[ReefChoice]

Hi guys
Sounds like your were going through a rotifer density and possibly enrichment issue.
Keep this in mind... Rotifers are empty shells without enrichment and require a solid 2-4 hours prior to sieve, rinse and add to the larval culture. If it was the first few spawn it very possible and common that the eggs are low quality as the parents start getting their bodies in check.
I would stay away from adding any peroxide to your cultures... Especially if your using live algae.
Peroxide is a strong oxidizer and while it will reduce ammonia, kill bacteria it and algae ... It's also very taxing on the gills of fish and while you may not have an issue now when they get a bit larger you may encounter issues.
Chloram X is cheap and safe for human consumption.
I currently have 123 spawning Broodstock and routinely have 85-90% success on all varieties of clown, gobies, psuedochromis and cardinal

Food for thought you'll need allot of rotifer! And artemia good quality enrichment and sterile conditions to avoid deformities.... Worst thing is to bring up a few hundred and find out 4 months later you have a ton malformed fish :-/

[onsan]

Difference between medicine and poison is dosage and administration.
Used as directed above, peroxide will not interfere with bacteria, algae or fish to any significant degree. The ionic reaction with ammonia (and other reactive ions) is much quicker than that of unicellular and multicellular organisms, and will not remain in solution for more than a few minutes to have any lasting effects.

I wouldn't be recommending any formaldehyde based product as safe for human consumption.