Biocube chaeto issue

I'd just remove th cheato. Unless you are using it to help grow pods, the area you have to work with is much to small for nutrient control.

 

If all parameters are at 0 then the chaeto would have nothing to eat and is dying off or there is another trace element that is depleted, possibly iron if you notice it yellowing. I have never heard of anything significant leaking from purigen or carbon but from the context I think you mean that the carbon is absorbing nutrients or elements the chaeto needs and that would be my guess too. Can always try a different source of chaeto, I bought my chaeto off ebay before I knew about GIRS. I keep chaeto in my intank basket on my biocube 14 and it overgrows the container if I wait much over two weeks before harvesting, that being said I run a small amount of carbon and GFO too. 3 weeks after last water change phosphate is 0.00 via hanna colorimeter and nitrate undetectable via salifert test. Sometimes the edges of the “ball” become discolored and when I harvest I just remove all growth that isn’t bright green, I was thinking of iron supplementation, but it’s working so well for my system there is no point messing with it.

If all your levels are 0 and you are happy just take it out. Otherwise you can add some trace elements and remove the carbon. Any organically bound iron supplement will work for a reef tank.

 

Chaeto seems to be effective my tank's nutrient control despite the small size so I decided to try and look into this issue and see if I could quantify chaeto or any other algae nutrient removal. I found this paper:

http://diposit.ub.edu/dspace/bitstream/2445/32444/1/523039.pdf

Now this isn't exact, but should give a decent approximation. They used 10g chaeto (wet) and over 10 days it gained 13mg N, and 1.7mg P (dry). Now lets say my biocube has 10gal water (it really has about 6gallons with everything in it), if I had 1ppm phospate that would be 10g=38,000ml x 1ug/ul (1 PPM) = 38,000ug

38,000ug = 0.038g PO4 divide by 3 to get total P = 0.013 or 13mg total p in tank from PO4. (6.5mg total P if inital PO4 was 0.5ppm)

Since the papers 10g gained 1.7mg P if one used 10x that amount or 100g (wet) chaeto that would absorb 17mg/10days which is quite a bit more than 1ppm in 10 gallons.
Really 40g chaeto would be effective in removing 0.5ppmPO4 from 10 gallons in 10 days or .05ppm removed per day. If you didn't feed more than that amount the chaeto should keep levels almost undetectable. Of course my tank is less than 10g water, so there wouldn't be that much total PO4, but this is just "for fun".

Now I just need to weigh my chaeto next clean out and see what the wet weight is. If I did this wrong please correct me. Nitrate is about 0.000062g/umole and PO4 is 0.000095g/umole if that saves anyone looking it up.

 

If you're using it for nutrient control and it's starving, that's a good thing. /DesktopModules/ActiveForums/themes/_default//emoticons/smile.gif