Calcium Bleedin' Sulphate

[Vale!]

This morning all glassed Daphnia answered roll call. They were informed that their mission had come to an end ; they were thanked for their service and given a ceremonial escort back to the bath.

The floor is still dry!

I retrieved the milk carton from the freezer : all but maybe 100mls was frozen. I let it all defrost and poured it out into four glasses as before. The fourth glass revealed that solution was not quite complete :



I was torn between putting it back in the freezer to see if another 24hrs would make a difference, or letting it warm up to ambient to try to assess whether anything would come out of solution. I chose the former for now.

[Mito]

I'm wondering if a residue of amber nectar on the glasses is interfering with the alchemy.
Can I ask why you are doing this experiment, to introduce genetic changes in Daphnia? I really am interested to know, honest.

[Vale!]

I'll spill the beans when I can get on my PC - Grandperson is hogging it at the moment - and I can type much more comfortably anx accurately. I guess on the morrow, Good Sir!

[Vale!]

@Mito

I have a number of nano tanks that were once used for fishy reasons and could be again at very short notice. While they're not being otherwise used they house live fish food - mainly Daphnia, blackworms and Asellus but with all sorts of hangers-on, too. In the Summer they typically live outside (to generate mosquito larvae) and, again typically, in Winter they're brought inside, with water-changes being done with water from fish-stocked tanks (plus a little bit of KH). Here are some caught green-handed in their lurking spots in the garden just now ...







I'm going to try to combine their contents into one tank indoors to reduce maintenance effort and to increase productivity during the Winter. I'm hoping to incorporate a small 'green water' generator to supplement the
indoor diet that they they usually get. This may well not work as intended, but I'm going to give it a go anyway!

If you've ever looked at YouTube videos about culturing of Daphnia and/or 'green' water, a minor point is that the majority seem to feature outside cultures but in tropical climes and make no reference to how to mitigate an English Winter! The major point is that when they pour water into a bucket they never ever say what the water quality actually is! Milton Keynes chloraminated tapwater appears to be a no-no because, as I've discovered, treating with dechlorinator (at least with Seachem Prime) kills blackworms. Local rainwater is crap for the purpose. So I figured I would need to make up the 'right' water, using RO and salts, to maximise chances of success.

In my search for the 'ideal' culture water I came at last across an article attached to a university-run schools programme in the USA for biology students. It contains a recipe for water ideal for my purpose - one that their labs use for successful Daphnia culture : http://www.ei.cornell.edu/toxicology/bi ... lture.html

It specifies calcium bleedin' sulphate, as you see, but doesn't seem to give any advice on how to get it into solution! Apparently the closer it is to its freezing point, the more dissolves. The other components dissolve easily, so what I'm aiming at is getting a saturated solution of calcium sulphate that I can decant proportionately into a prepared mix of the other ingredients. With a bit/lot of luck I my be able to prepare 3L batches of it in a milk carton (that'll fit in the freezer) and will enable several 10% water-changes in the tank that I'm currently preparing. I'm still feeling my way, so maths hasn't yet come into it! I comfort myself with the thought that the probability of success is greater than zero!

The experimental carton is out of the freezer this morning and defrosting, being shaken every so often. One of the great unknowns (to me) is whether calcium sulphate precipitates when a saturated solution is warmed up, so that's next on my 'to do' list! I wish I'd paid more attention to Mr. Smiles in A level chemistry!

[Vale!]

I took all the Heath-Robinson plumbing out of the barrel and let it settle for a couple of hours. Couple of pics of the glass test ...





It's pretty much all dissolved after 3 days of constant stirring. Conductivity was 305uS, pH was 7.07 and temp 29.4C (hotter than ambient because of the pump's heat I expect?).

So if I needed to prepare a big batch of change-water I could use this method. I should buy some proper hose, I guess!


The milk carton came out of the freezer, defrosted with more shaking and poured sequentially into the four pint glasses. Here's the fourth glass ...



Conductivity in the glass was 538uS, pH was 6.31 and temp was 19.5C

If anything it's a better solution than the barrel managed - it's close enough for jazz and I'm going to call it a win! The milk carton has now reached ambient temperature and all looks good.

I should be able to get 1.2g dissolved if I increase the volume to 3L. I can't really go any bigger than a 6-pint milk carton else Mrs. V! would go ballistic. Mind you ... earlier there was the most astonishing rain storm. In fact so intense was it that Mrs. V! took the opportunity to have a shower in her undergarments* ; I took a photo. It's now my desktop wallpaper, but I'm not averse to a little blackmail every now and then.

Anyway if my maths is unusually correct, a 3L milk carton of calcium sulphate solution will allow me a 15.7% water-change in the 68.4L that Sheba 4 holds. The procedure looks like this ...

Three days before a water-change is anticipated, fill the milk carton with 3L of RO/DI and add 1.2g calcium sulphate powder. Put in freezer. Try to remember to shake it up every so often. At the same time put 7.8L of RO/DI into a barrel (I might try to buy one of a more convenient size) and add : 2.07g of sodium bicarbonate ; 1.2g of magnesium sulphate ; and 0.08g of potassium chloride. Remember to shake that, too! Then on the day of the change, pour the contents of the milk carton into the barrel.

I think I can live with that, just about.

And I think that probably wraps up the thread!







* I use the plural out of a sense of decorum, you understand.

[Vale!]

I'm reopening this thread, just a crack. Look through : there you see me sitting at the table in my 'fishroom'. Empty stare. Glass of brandy. Revolver.

Sheba 4 was going so well. Having cleaned it out and re-established the cycle (which was flying) I thought I'd move on to the next stage: to begin to get the water parameters where I wanted them. Remember that 25 litre barrel containing the 'ideal' mix of calcium bleedin' sulphate, sodium bicarbonate, magnesium sulphate and potassium chloride? How could you forget it! Anyway I used that barrel to water-change Sheba 4 - around a 30% change.

Next day the cycle had stopped, dead.

Now the last time I had a haircut was February 2000 (for an interview) so, allowing appropriately for age, you might say that I've a reasonable amount of stuff to tear out ; which is precisely what I had been doing.

Then, during a bout of frenzied testing I found a phosphate concentration of greater than 5mg/l. Had the filter crashed for some reason and released a load of phosphate in its death throes? Surely too much phosphate for that to be the case (it had been a relatively lightly-stocked tank, fishwise).



Now I'm going to pause there and encourage those of you who have already guessed what happened to laugh and point at me. You may laugh raucously and use words such as 'numpty' and dip****.

If I can keep my distance from that revolver, I'll return when the mocking has finished to explain further.

[Mito]

I think I'll stick at "Oh dear, what a pity"

[plankton]

Errrr....oops?!

[fr499y]

Bugger! Did you forget to put the filter back on?

[Vale!]

'Pity' is probably the right reaction!

'Oops' indeed!

No - the filter was running the whole time.

[Think : schoolboy error!]