Is this a good price estimate for rotifer cultures?

[LordJoshaeus]

Hi everyone! Here is a question that I do not need a scientific article to answer...I was creating a price check to estimate how much it would cost for me to keep up with two 1 gallon rotifer cultures. How does this sound?

Costs for two 1 gallon rotifer jars;
- 15 watt heater; .26
- Isochrysis culture; about $1.02 (if water is recycled)*
- Air pump (4 watt, 2 lines); .21
- 19.5 liters DI water (twice weekly 30% WC's, assuming new water is used); $.48
- 40 TBS instant ocean (using Chewy to acquire the salt); $1.18

TOTAL;$3.15 (assuming the rotifers use new salt water and the isochrysis uses recycled water...in all fairness, if I did 30% WC's twice a week on these rotifer cultures I could easily recycle enough water from them for double the below amount of Isochrysis or even to start cultures of a different algae species)

*Monthly Isochrysis culture costs (for two 2 liter cultures);
- BR20 LED light bulb (6 watts, 12 hrs/day); .16
- 1 gallon saltwater/week (1/2 gallon per culture); Nothing? (if I already have a
saltwater tank. A 1 micron filter sock and/or .4 ml bleach per gallon for 30 minutes
would be used to sterilize the water. Bleach/sodium thiosulfate reaction is
4 NaOCl (bleach) + Na2S2O3 (dechlor) + 2 NaOH → 4 NaCl + 2 Na2SO4 + H2O). May add
baking soda to the water as an inorganic carbon source; .15 ml baking soda
adds 1.2 degrees KH to one gallon of water.
-If I REUSE old tank water;
*Sodium thiosulfate; Trivial
*Bleach; Trivial
-If I DO make new water;
* Salt; .74
* DI water; about .2
- Glycerin (about .5 ml/gallon, 10 oz=226.19 grams); about .05 (may also add glycerin
to Iso being kept in fridge to give it an energy source)
- F/2 fertilizer; about .34
- 4 watt air pump; .21
- 15 watt heater; .26

TOTAL; About $1.02 (assuming water is recycled from display)
- If water is made new, $1.96

One other thing...is there any particular reason I could not harvest the rotifers and/or algae on a 1 micron sieve before using them? I would think, assuming that did not kill or mortally wound the rotifers/algae, that this would reduce nutrient accumulation inside the larval tank by keeping nutrients (especially from the algae cultures) out of the tank. Thanks for your input

 

[Tankkeepers]

I cant say for sure but it looks like you have accounted for everything including electric good on you and if your math is accurate then id say you awnsered your own question

 

[Tankkeepers]

And usings a sieve shouldnt hurt anything (may be wrong here)I used to use an unbleached coffie filter

 

[ichthyogeek]

It looks good to me? Are you keeping the rotifer jars in a tub to share the heater?

You could harvest everything on a 1 micron sieve, yes. But remember that you have to account for your own time. I have a hard enough time waiting for water to drain out of a brine shrimp net, and while you can do a few things to quicken the drainage time (like a backwash), 1 micron is still going to drain quite slowly, and might even clog.

Drain and rinse your rotifers on something like a 53 uM sieve; it keeps the rotifers in, but lets the contaminants out.

For the microalgae, you could certainly drain it into a 1 uM sieve, but aiming for the largest size possible is a better idea. But if you're adding live microalgae into the rearing tank, don't they need some of the excess nutrients in order to keep reproducing?

With a larval tank, your better bets are to do water changes and keep macroalgae somewhere in the system. Worry about the big producers (fish larvae) and not about the small producers (trace nutrients added to the tank with microalgae).

 

[LordJoshaeus]

It looks good to me? Are you keeping the rotifer jars in a tub to share the heater?

You could harvest everything on a 1 micron sieve, yes. But remember that you have to account for your own time. I have a hard enough time waiting for water to drain out of a brine shrimp net, and while you can do a few things to quicken the drainage time (like a backwash), 1 micron is still going to drain quite slowly, and might even clog.

Drain and rinse your rotifers on something like a 53 uM sieve; it keeps the rotifers in, but lets the contaminants out.

For the microalgae, you could certainly drain it into a 1 uM sieve, but aiming for the largest size possible is a better idea. But if you're adding live microalgae into the rearing tank, don't they need some of the excess nutrients in order to keep reproducing?

With a larval tank, your better bets are to do water changes and keep macroalgae somewhere in the system. Worry about the big producers (fish larvae) and not about the small producers (trace nutrients added to the tank with microalgae).

Yes on the shared heating tub. If the 1 micron sieve is too slow, I have no beef using a 53 micron sieve for the rotifers and skipping it entirely for the algae. By the way...how much algae do rotifers need for a decent culture? I was hearing 60,000,000-70,000,000 cells per ml, which seems impossible to meet without absurd amounts of algae paste or enormous algae cultures...is that the figure for industrial production with thousands of rotifers per ml rather than the usual figure in the hundreds for hobbyist cultures?

EDIT: I forgot...I am finally taking definite steps towards actually getting a saltwater tank Getting 50 gallon's worth of marine salt at petco this morning in a curbside pickup. I will most likely get it in bulk on chewy in the future for cost reasons (unless I cannot find anywhere to store that much salt), but it's a start! I decided that if I did not do something decisive soon, I would never get rolling at all.

 

[andrewkw]

You need a lot of phytoplankton for rotifers. I've never tried to add up the costs, but if you are on a really tight budget or are adding up every last cent for another reason, make sure you account for both crashes and potential cross contamination.

When I got my rotifers I had to spend double because the first batch sucked. Then worse I tried to salvage some and cross contaminated the clean ones. I've since cleaned them up to be usable but I don't believe they are 100% clean. Finally I am having trouble producing enough phyto for them. I had just one 2L crash but that is an issue.

If your budget allows I would consider having at least 1 bottle of RG Complete. Overall this is a much better albeit more expensive food option for your rotifers. If there was an LFS near me that could supply it to me without having to pay crazy shipping fees that's all I would use. Since there isn't I typically feed RG one time a day and phyto the other, but there are times where I have to use RG both times. I do have three 5 gallon buckets of rotifers though, I don't need this many so I probably should reduce the 2 backup cultures to a smaller size but I am paranoid about either a crash or serious cross contamination and not being able to produce enough for my fry.

 

[MabuyaQ]

Always use new water for your phytocultures and be aware that cross contamination is a given if you don't keep the rotifers far enough away from your phyto.

 

[LordJoshaeus]

Always use new water for your phytocultures and be aware that cross contamination is a given if you don't keep the rotifers far enough away from your phyto.

I was going to sterilize the old water with a small amount of bleach first for half an hour to 45 minutes, then dechlorinate that and set it aside for culture use. Yeah, if I do keep live algae cultures they will be nowhere near the rotifers if I can help it.

 

[MabuyaQ]

My experience is that phyto is far more sensitive to (changes in) the chemistry of the culturewater than zoöplankton so is less likely to crash with newly mixed water. You can use sterilized tankwater for zoöplankton, just make sure salinity doesn't change when setting up a new culture of rotifers as this will stall their reproduction. A small salinity drift over time doesn't impact reproduction though.

 

[Tankkeepers]

All looks good here but I will add be very carfull not to contaminate your cultures with Salmonella it can very easily contaminate phytoplankton I had this happen when culturing nannochloropsis

 

[LordJoshaeus]

All looks good here but I will add be very carfull not to contaminate your cultures with Salmonella it can very easily contaminate phytoplankton I had this happen when culturing nannochloropsis

Salmonella is an issue in the aquarium hobby? Assuming I culture the algae and do not use a paste, I was going to use bleach to sterilize the water for 30-45 minutes before dechlorinating the bleach and setting it aside for use.

 

[Tankkeepers]

Yep it can come in on your hands if not careful thats how mine was contaminated didnt clean my hands well enoff after handling chicken and then I touched the culture to move an air stone and bam contaminated

 

[Tankkeepers]

And you cant see that's its contaminated but it will grow producing toxins and the toxins can wipe out an entire tank had it happen id recommend covering all your cultures so nothing air born can get into them creating a positive pressure inside the culture and making sure your hands are clean clean clean before handling them

 

[Tankkeepers]

Your on the right track with sterilization tho after each batch

 

[Tankkeepers]

I was using my cultures to feed non photosynthetic sponges gorgonians etc it did not end well had to restart everything was a very sad day

 

[Tankkeepers]

Also wiped out my brine shrimp cultures

 

[Tankkeepers]

Ps I kept my cultures at 1.018 salinity so a higher salinity may keep it from happening but I would not chance it

 

[Tankkeepers]

I'm trying to find the data for you but google is not cowoperating with me was 8ish years ago I had this happen

 

[Tankkeepers]

Errr cant find the old journals wish I had them saved all I can find is how to make biofuel go figure sry

 

[Tankkeepers]

Bacterial contamination is always a risk with anything that you culture adhear to lab grade handling and culturing and you will not have any problems mostly just make sure your hands and whatever you are using is clean and sterile and create a positive pressure inside the cultures and you will be fine