I keep killing my rotifers

I keep killing my rotifers.
1. I use RODI water mixed with IO salt. I make sure the salinity is always with in .007. Generally speaking, I always keep my broodstock between 1.015 and 1.020, so that I can use the same NSW for rotifers as well. Generally speaking though, my rotifers are usually 1.015.
2. I change 33% of the water daily - I don't really harvest the rotifers with a sieve, I simply dump 1/3 of the water out after scraping up the sides/bottom of the bucket. My trick is to dump 95% of the water into a new bucket, leave all the crap in the old bucket, and then remove 30% of the water from the new bucket, thus ensuring I'm removing ALOT of the crap every day.
3. I've fed with RGC, now I switched to RG+ and chloram-x - I have been following Tal's website for instructions for a few days. For the chloram-x I did 12 teaspoons per 500ML solution, dosing 5ML per day per culture - sometimes double dosing by accident. I wasn't measuring the RGC. That might have been a problem.
I'm on try #6.New rotifers coming in tomorrow. I plan to continue following Tal's website. My cultures may have been bad during the transition from RGC to RG+
 
Q1. Is there anything in tap water that might not get removed by RODI that is harmful to rotifers? My town's water system was severely polluted 30+ years ago. I'm wondering if there are chemicals that aren't removed by RODI system.
Q2. What about aged NSW? Sometimes my water sits in the barrell for a week before I use it. Is this a problem?
Q3. Should I be sterilizing these buckets? Sometimes they are getting used for water changes on the broodstock tanks.
Q4. I can see some dust in the buckets, but I can't tell if they are rotifers, ciliates, or something else.
 
My BBS culures look more like rotifers than my rotifers. I sometimes wonder if I contaminated that with rotifers... =) I see millions of swimming things in that culture, with very few visible shrimp.
 
I've been reading the forum alot, and nothing is jumping out at me as to what my problem could be.

I don't use any ammonia treatment in my rotifers but 5ml per day seems way overkill. I would have to look back to what I was feeding when I was using rots but I think it was like 1ml of RG+ twice daily. I would suggest feeding along those lines and recheck the chloram-x dosage too. You are doing good by changing 30%. I never changed near that much.

Thx for the input Waldend. I was referencing this for my chloram-x dilution.
 
http://www.mbisite.org/Fo...277&high=chloram-x

So to me it looks like that mix is your issue. Hopefully I am looking at this right but I will type it out so you or others can doublecheck my logic.

There was debate in 12/16 tsp per liter but you said you mixed yours to 500ml so I think you are already double strength. The 12tsp per 1 liter was to give a 1:1 to RG+ usage. I think for s single bucket culture using 5ml of RG+ per day is a little strong and at your strength of Chloram-x you would need to be feeding 10ml of RG+ per day. Then if you were sometimes double dosing I think you were pushing way over the safety limit.

As I said before I never dosed any ammonia treatment so I might be a bit biased but with your large water change per day I would think you really need minimal. If I were you I would feed 1ml of RG+ twice daily. With first feeding I would add 1/2 ml of your solution max. I think you will see much better results, but if not we will help figure it out! No stopping until you are the rotifer king!

I agree with Waldend, it seems like too much chloram X. I use a mix of 16 teaspoons per liter of RODI water to make a solution that I then add at a 1:1 with the rotigrow. The most I add to my 5 gallon cultures is 2ml of each per day.

I accounted for that. I mixed 6 teaspoons per 500 ml.

I keep killing my rotifers.
1. I use RODI water mixed with IO salt. I make sure the salinity is always with in .007. Generally speaking, I always keep my broodstock between 1.015 and 1.020, so that I can use the same NSW for rotifers as well. Generally speaking though, my rotifers are usually 1.015.
 
As a side note, 1.015 is really low for broodstock imo.  I recently found my S.G. to be 1.018 and I'm pretty sure this was causing me some issues with my broodstock.  All my broodstock is (supposed to be) at 1.020 and FWIW, I use the same water for my rotifers.  I know rotifers prefer to be closer to 1.015, but in all honesty, I haven't noticed a difference in their production when I started keeping them at 1.020.  I just use carbon filtered tap water for the whole fish room, and top off with RO/DI. 
 
2. I change 33% of the water daily - I don't really harvest the rotifers with a sieve, I simply dump 1/3 of the water out after scraping up the sides/bottom of the bucket. My trick is to dump 95% of the water into a new bucket, leave all the crap in the old bucket, and then remove 30% of the water from the new bucket, thus ensuring I'm removing ALOT of the crap every day.
 
The 1/3 rule is for the best practices, though I've found it is not needed.  If I am actively using a culture because of several larvae batches at the same time then I may use 1/3 of each culture per day.  I tend to use a much more relaxed protocol. 
 
I add water to each bucket everyday or every second day.  Once a week or so I will save 500 mL of culture and dump the rest out, gently brush the gunk out of the container, but don't scrub it too much, put the 500 mL back in, and add 500 mL new SW.  My cultures are in 3.5L containers (they are like ice cream pails except they are dark grey). 
 
These cultures will get so dense that they are usually not even half full, and I can maintain batches of several hundred larvae.  The rotifers will consume up to 3 mL RotiGrow+ per liter of culture if I let them.  I don't let them - that costs too much.  Haha!  If they get this dense, I dump them, and restart with 500 mL.

 
3. I've fed with RGC, now I switched to RG+ and chloram-x - I have been following Tal's website for instructions for a few days. For the chloram-x I did 12 teaspoons per 500ML solution, dosing 5ML per day per culture - sometimes double dosing by accident. I wasn't measuring the RGC. That might have been a problem.
 
I saw your correction above, you are actually using 6 tsp in 500 mL, right? 
 
5 mL is a lot - way too much for a new culture imo.  You should feed twice a day, BUT when you feed, the water should be completely clear of food.  If the water is not clear, skip a feeding.  I think feeding when the water is NOT clear is the best way to crash a culture.
 
If you are starting with the Reed bag of 1 million rotifers, you will only need to feed about 0.5 - 1 mL per day at first.  Do not dilute the bag more than 1:1 when you start.  So if the culture is about 1L or so, then put 500 mL into each culture bucket, and add 500 mL new SW.


Q2. What about aged NSW? Sometimes my water sits in the barrell for a week before I use it. Is this a problem?
 
Assuming you mean "new SW", not "natural seawater" (NSW), then there is no issue with the ASW (artifical seawater) being mixed up for longer periods of time.   My tub of ASW is always mixing.
 
Q3. Should I be sterilizing these buckets? Sometimes they are getting used for water changes on the broodstock tanks.
 
I would not be switching up the buckets.  Get some smaller buckets for the rotifers and keep them as rotifer ONLY buckets.
 
Q4. I can see some dust in the buckets, but I can't tell if they are rotifers, ciliates, or something else.

My BBS culures look more like rotifers than my rotifers. I sometimes wonder if I contaminated that with rotifers... =) I see millions of swimming things in that culture, with very few visible shrimp.
 
You need a microscope.

I've been reading the forum alot, and nothing is jumping out at me as to what my problem could be.
 
I'm pretty sure you problem is mainly that you are overfeeding.  I think you will do better if you use much smaller buckets too.  I have no idea why people lug these 5-gallon pails of rotifers around when a 4 or 6L bucket will surely do.  How many larvae do you ever have at any given time?

Don't let fear and common sense stop you! =]

Thank you Mindy! I love it that you are using smaller volumes.  It really gets costly maintaining large volumes of rotifers, in both clean saltwater, and rotifer food, and for my needs, it isn't necessary.  A couple of small dense populations of young rotifers really is enough, and is significantly less labor intensive.

check out Kathy's Clowns, llc website:
http://kathysclowns.com
Captive bred clownfish and more
(Wholesale to the trade.)

Thanks for the response Mindy.
 
I thought my salinity was actually good. I've gotten 4 out of 5 pairs to spawn in very little time. I guess that's just luck and not attributed to my low salinity.
 
I thought ASW meant AGED salt water. So mine would be aged artificial saltwater, meaning it's been sitting in my brute trash can for awhile.
 
Does any one ever use broodstock water for rotifer water changes. Does Nitrate negatively affect rotifers?
 
Silly question. You can safetly bump rotifer salinity from 1.015 yo 1.021? (.005.) Just making sure.
 
Mindy I'm intrigued by your small cultures. I have two of those CCS from Reeds. I'm thinking maybe I should run those 1/2 full to save on feed.
 
I saw your correction above, you are actually using 6 tsp in 500 mL, right?
 
5 mL is a lot - way too much for a new culture imo.  You should feed twice a day, BUT when you feed, the water should be completely clear of food.  If the water is not clear, skip a feeding.  I think feeding when the water is NOT clear is the best way to crash a culture.
 
When you say 5ML is way too much are you talking about diluted RG+ or chloramx? 
 
I take 500ML of SW and dilute 6 tsp of Chloramx and I was dosing 5ML of that daily.
 
If you are talking about RG+, I fill a 2L with SW and dilute 50ML of RG+ per Tal's site. I then feed 10ML twice daily per gallon of rotifers. So in my case, 40ML twice per day per culture - cultures have 4 gallons.

 
I have two batches of Fry right now in my BRT. They were small batches. I'd say I have 100 fry between the two batches. My BRT is too big too. It's a short 15G oval. I had to fill it in order to get the eggs under water. I think i'm going to drain some water to keep the volume down. Keeping the volume of rotifers up in 13G of water is not easy.
 

Also, I just picked this up on Amazon...http://www.amazon.com/Cel...s=celestron+microscope
 
Mindy, I see your advice on page 135 of Wittenrich's book regarding allowing the cultures to go clear/tea colored.  I read somewhere else NOT to do this which is obviously someone else's opinion. Thanks for setting me straight.

 
Yes, it ends up being a clear, yellowish color.  Certainly not green anymore.


 
You're welcome!  It is much cheaper.  I was keeping bigger cultures when I first started and I was going through almost 20 mL of RotiGrow+ per day.  That's over 7 liters of RotiGrow+ per year, and it costs me over CAD$120/L here in Canada once you add exchange rate, duty charges, and shipping.  That's over $800 per year!
 
Does any one ever use broodstock water for rotifer water changes. Does Nitrate negatively affect rotifers?
 
I've never bothered.  I don't like to have "used" saltwater sitting around, and I only use about 6-8 cups of new SW per week for the rotifer cultures anyway.
 
Silly question. You can safetly bump rotifer salinity from 1.015 yo 1.021? (.005.) Just making sure.

Not sure.

When you say 5ML is way too much are you talking about diluted RG+ or chloramx? 
 
I'm talking about undiluted RG+ (plus equal amounts of ClorAm-X solution).
 
I take 500ML of SW and dilute 6 tsp of Chloramx and I was dosing 5ML of that daily.
 
Ok, that's the same dilution I use.

 
If you are talking about RG+, I fill a 2L with SW and dilute 50ML of RG+ per Tal's site. I then feed 10ML twice daily per gallon of rotifers. So in my case, 40ML twice per day per culture - cultures have 4 gallons.
 
You're not supposed to dilute RG+ except only immediately prior to use.  Diluting RG+ will damage the cells. There is no reason to dilute it anyway.  When I buy 1L of RG+ I pour 100 mL into 10 plastic bottles (for medicine), and put them in the freezer.  I pull one out when needed, thaw, and use directly from the bottle with a syringe with a small length of airline tubing attached to it.  RG+ will go bad in about 30 days in the fridge I find, so I make sure that I use up each bottle within 30 days.  I mark the date on the bottle that I thaw it out.
 
The dilution of the ClorAm-X you have above is the dilution rate for use with equal parts of undiluted RG+, so you are heavily overdosing ClorAm-X.
 
I have two batches of Fry right now in my BRT. They were small batches. I'd say I have 100 fry between the two batches. My BRT is too big too. It's a short 15G oval. I had to fill it in order to get the eggs under water. I think i'm going to drain some water to keep the volume down. Keeping the volume of rotifers up in 13G of water is not easy.

I use 5, 10, and 20-gallon aquariums depending on batch size, and they stay in these tanks until they are 30 days old.  I find I can raise about 25 larvae per gallon.  The aquariums are painted white on the bottom, and black on 3 sides.  I leave one short end un-painted (this is the "front"), and I tape a black facecloth to it.  This way I can check the Ammonia Alert and view the larvae from the side.  Once they go through meta, I remove the cloth. 
 
I do 30% water changes daily starting at about day 3, and when they are approaching 30 days, I do 50% per day.  I need to start testing nitrate to see if these water changes are actually needed.  Although I'm not sure if the nitrate is what is affecting them or something else (bacteria? low minerals?).

Don't let fear and common sense stop you! =]

I will add a note in regards to consumption rate of RG+. If you know you don't need rotifers just start feeding less and the population will slowly decrease. When I didn't need then I would feed maybe 1ml of RG+ per day and didn't worry if I forgot a day. i also wouldn't do any water change or harvest during this "conservation mode". I could go several weeks this way before I would see a significant decrease in the rotifer population. At that point I would sieve all the rotifers from the water, add about 2-3gallons of new ASW to the bucket and then add the rotifers to it. I would then continue the 1ml per day for a few days to allow the population to start growing and then resume to heavier feeding for a full ramp. I wouldn't necessarily recommend this starting out but once you get the feel for keeping them you will fine.

Also, the rotifers can take a .007 sudden change in salinity with no issues.

Is there a magic number for Chloramx dosing? I have the dilution correct, now I need to know how much to feed. Is it just equal parts chloramx dilution to undiluted rg+? Since I was using diluted RG+ that makes it a little confusing. If I go back to the concentrate, how much RG+ should I use? 1ML undiluted for less than 5g cultures?

The rule of thumb is your current strength of chloram-x 1:1 with undiluted RG+.

I would start with 1ml per day of undiluted RG+. The population will grow to match the feed rate you are using. Get used to doing the 1ml and then start experimenting with higher feed rates and densities.

President....  yes, do not use broodstock water for your rotifer water.  Too many contaminants.  Its a great way to turn a clean culture into a dirty one.  We go to great lengths to keep our cultures clean, you're getting the cleanest culture available for resale.

Thx All.
 
All how are you viewing rotifers under a microscope? Just a slide and a pipette? Petridish? My microscope came today, and I'm having a hard time viewing the rotifers. I did see one, but my drop of water runs off my slide.

Sedgewick-Rafter
http://pentairaes.com/cou...-sedgewick-rafter.html
 
at least to count them.
 

or put a cover plate on the slide

Thanks Gresham. Wow those slides are expensive!

Wow, expensive.  Here's a poor man's way: got an old swing arm hydrometer? Draw a circle around a dime with a sharpie on one side.  Fill the hydrometer until its over the circle with rotifer culture.  Estimate/count the tiny swimming dots within the circle, and that number is a good approximation of how many rotifers / ml culture you have.

check out Kathy's Clowns, llc website:
http://kathysclowns.com
Captive bred clownfish and more
(Wholesale to the trade.)

Another way is to put a drop on a clear rigid piece of plastic.  Hold a flashlight on it, and count the swimming dots. multiply by 20-25, and that's a good estimation of how many rotifers/ml.  If you don't see any rotifers in one drop, try 5 or 10, and multiply by 4-5 or 2-2.5.  The reason I'm giving you a range, is that, depending on the dropper, you may have anywhere from 20-25 drops per ml.  If you can measure that, you can determine the size of your drop, and what the multiplication should be.

check out Kathy's Clowns, llc website:
http://kathysclowns.com
Captive bred clownfish and more
(Wholesale to the trade.)

Thanks Kathy! The second way sounds easiest since I don't have a hydrometer anymore. I actually just put away my refractometer and bought a digital one. I'm nearsighted, and was having trouble reading it. The digital one rocks.
I did find a poor man way to view rotifers under my scope. I took the lid off a salifert test container and filled that with culture water. I cannot count this way because my microscope has 4x, 10x, and 40x, and even the 4x is way too big - i can only see 1 or 2 rotifers at a time. Considering returning it, for something that I can count with. I don't like squinting through a loupe either.

 
Yes, 1:1 ClorAm-X solution (mixed as above) to undiluted RG+.  You feed the rotifers to the number of rotifers, not the volume of water.  So, if you have 1 million rotifers in 1 liter you feed the same amount as if you had 1 million rotifers in 5 gallons.  It is certainly better to underfeed than overfeed as far as the rotifer culture goes. 
 
If you are feeding the rotifers to fish larvae though, you don't want to feed starving rotifers.  I'm not sure the exact timeline, but 6 hours with no food is certainly starving.  My rotifers are always starving because they go through their food for the day within just a few hours.  For this reason, I "gutload" rotifers aka "enrich" them before feeding the larvae.  I sieve the ones I want to feed, put them in a small cup with light aeration for an hour with a small amount of RG+, then sieve them out into the larvae tank.  I dump the cup water into one of the rotifer cultures so I don't waste any RG+ since they will not eat it all in an hour.
 
I used to use N-Rich PL Plus to enrich the rotifers, and it worked VERY well as far as the quality of larvae went, BUT the smallest size is 1 liter, and I would never use up near all of it.  It's expensive, and I was dumping most of it.  It's a great product, and it's a shame it's not offered in 250 mL size.  I've requested many times over the last few years.

Don't let fear and common sense stop you! =]

The rule of thumb that Randy/Reed presented for rotifers was that 1hr in a rotifers life is like 1 day for a person. This was to stress the importance of having food available for the rotifers at all times.

Gresham can, and I am sure will , correct me if I am wrong but I think RG+ was designed to not require enrichment.

Oh there is cheaper, and other solutions.  Thats just a link I had to illustrate what I am talking about.

 
I could be wrong, but I suspect that your stage objectives have the 4x, 10x, etc. markings, but the eyepiece objective boosts that another 10x, making it 40x, 100x, 400x.  Viewing at a total of 10x-20x is ideal for counting rotifers, in my opinion.
 
You hae a celestron, correct? you can buy slides on amazon that have a little well in the center relatively cheaply, and that is ideal for looking at living critters in water.  You can also get some little glass coverslips to protect your objectives and just set them on top of the filled well for viewing.
 

check out Kathy's Clowns, llc website:
http://kathysclowns.com
Captive bred clownfish and more
(Wholesale to the trade.)

I think I had the digital zoom on. This is the one I have.
http://www.amazon.com/Cel...keywords=celestron+lcd
 
Do I basically have to buy a kids version to get such a low magnification?

 
Yes, RG+ is designed to feed the rotifers in such fashion that they do not require enriching.  However, I was referring to the fact that if you have a high density and you don't want to feed to the density (save $$$) that they will be starving between feedings, and WILL require "enrichment" either by allowing them to feed on RG+ for an hour before harvesting or some other "gut loading".  OTOH, I can definitely attest that enriching RG+ fed rotifers with N-Rich PL Plus does make a difference!  I'm not sure that RG+ fed rotifers are nutritious enough for non-Clownfish (or other basics), so enriching may certainly have a role in the more challenging species.
 
My rotifers eat all their food long before their next feeding.  I don't want to harvest these guys with empty bellies.

Don't let fear and common sense stop you! =]

Anyone use one of these?
https://www.amazon.com/gp..._s00?ie=UTF8&psc=1
I've been pouring my entire culture through it daily, and then pouring around half through a reeds 40? um sieve to trap rotifers for feed. Anything wrong with that approach. I like it because it saves some time and effort. I do have 50 and 200 of those 5g bucket sieves, but at this point, they don't really serve a purpose. I'd rather use my smaller diameters at that mesh size.

Anyone use one of these to do counts? I found on the the Hoff Plankton Culture manual page 97 under step 3. It seems like a good way to count because the rotifers are restricted to each well.
http://www.ebay.com/itm/B...mp;hash=item3f2dcbb37e
 
I purchased this microscope. Had to order a replacement because the 20x lens was missing. 10x with 3x magnifier I can see the rotifers pretty well, except they are pretty clear so I had to use a black background.

I like those filters, except that sometimes they are too big and difficult to get pods off of.

check out Kathy's Clowns, llc website:
http://kathysclowns.com
Captive bred clownfish and more
(Wholesale to the trade.)

yes but I get them from US Plastic.  We tend to order a bunch at a time though.
 
http://www.usplastic.com/...id=24071&catid=685

link was originally not working - working now.

I wonder if you have to worry about knocking the eggs of rotifers like you do with copepods?  If that's the case, then sieving the whole culture would not be a good idea.  In any case, I think you are seriously over-thinking your rotifer culture.  I try not to handle my rotifer cultures too much because rotifers "have wings" and get everywhere.  I don't want them in my copepod cultures, so I only use small sieves on the rotifers and try not to touch them often.  The rotifer cultures are always the last thing I touch before I leave the fish room.

Don't let fear and common sense stop you! =]

Killing rotifers. I noticed my cultures not clearing. I sieved them all out, put a very small amount of old water in my bucket, added the rotifers, and added an equal amount of new salt water - total volume is around 2L. I really hate rotifers. .....
Mindy, i think you are right about NOT sieving the entire culture. I think that might be my problem.

Yeah, I think you're fussing with them too much.   When the culture suddenly doesn't clear as quickly as it normally does, I consider that a partial crash. 
 
Ime, there are a few main reasons for a crash; too much food, ammonia, not enough air, water is too dirty.  In that order too, I find the latter reason the least likely.  I've done experiments to see exactly what I have to do to crash a culture.  I purposely crashed cultures during the early days of my rotifer culturing so that I knew what the causes and limits were.  This is what I found:
 
- Overfeeding is the easiest way to crash the culture.  Grossly overfeeding (keeping medium green color in the culture 24/7) will cause crash as quickly as 3 days no matter the density.
- Ammonia killed them when I fed them correctly, left out the ClorAm-X, and didn't do waterchanges to flush the ammonia.  With high density, this killed them in about 5-7 days.
- Not enough air for the density can kill them very quickly, like 6 hours in a power outage.  The causes of low air usually build up over time - like a density that slowly overcomes the available air.  Generally, if there is not enough air, the density will only grow to the available oxygen content, not really crash.  BUT, if you sieve a culture to be denser, then don't supply them with enough air you will get a partial or full crash quickly.
- Dirty water will eventually kill them too.  So if I did everything else right, but I didn't do water changes or harvesting, the culture would eventually crash in about 10-14 days with a high density, MUCH longer for a lower density.

Don't let fear and common sense stop you! =]

I'm not pushing alot air through. Rigid airline with low to moderate air. Anyone use air stones? I've read they can clog.

NO air stones, a waste of good airstones.  Water should be "boiling" but not a "rolling boil".
 

check out Kathy's Clowns, llc website:
http://kathysclowns.com
Captive bred clownfish and more
(Wholesale to the trade.)

IME, course airstones.  Cost is nothing, you can get 100 of them for pennies on the dollar.

Still crashing the rotifers. I think my 1ML RG+ per 1 G might be killing the rotifers...I'm going to dump the RG+ i have on hand, and defrost some new cubes just to eliminate that as an issue. I think the tiny volume I had may have warmed up while I had it out. Very easy to warm up an ounce of liquid in just a few minutes.