how much phosban?
- Thread starter wnutz
- Start date
LobsterOfJustice
Recovering Detritophobe
I cant help yuou with the exact amount but I do know that you need to START OFF SLOW!. People have had issues of corals bleaching when starting this stuff. Start out with a little bit, then gradually work your way up to whatever amount you eventually settle on.
jdieck
New member
To avoid having to change the media too often, rather than using a small amount to start slow I would fill the reactor to capacity which is half way up (It will rise once fluidized) and then start slow by setting a small trickle flow and increase a bit every four days for full fluidization in a couple of weeks.
cerreta
Premium Member
buna, do you even have one of these units?
I use two reactors in a 80 galon system to manage phosphate problems and replenish the material about every 6 months. I run each reactor with 7oz of media thats roughly 200 grams in each reactor. Even the instructiond clearly state that the minmum use in a reactore is 130 grams.
The trick is not to over agitate the media in the reactor. You just barely want the surface of the media to be moving with the water flow.
I started running the reactor in this fashion immediately. I did not do a slow dosing or slow flow protocol, and I have not seen any troubles in my tank at all. If anything the tank looks much healthier with lower phosphates.
Good Luck
I use two reactors in a 80 galon system to manage phosphate problems and replenish the material about every 6 months. I run each reactor with 7oz of media thats roughly 200 grams in each reactor. Even the instructiond clearly state that the minmum use in a reactore is 130 grams.
The trick is not to over agitate the media in the reactor. You just barely want the surface of the media to be moving with the water flow.
I started running the reactor in this fashion immediately. I did not do a slow dosing or slow flow protocol, and I have not seen any troubles in my tank at all. If anything the tank looks much healthier with lower phosphates.
Good Luck
jdieck
New member
:lol: sorry that was not my intention but let me try to make it worst.
I just kept in reasoning that initially there is a good amount of phosphate in the tank dissolved in the water column and potentially in the rock and substrate. Using a very small amount means that you will have to replace it every three or four days.
Taking advantage that the media does not release any trapped phosphate and because after the dissolved phosphate in the water colum is removed the one trapped in rock and sand will start being released it may call for a lot of adsorption capacity needed for the first four to eight weeks so why to have to empty and replace the media 4 to six times during this initial period?
IMO using a small amount of media with a regular amount of water flow, saturation of the media will be fast, as media saturates the phophate stops being adsorbed and then start the cycle again once you replace it so the concentration of Phosphate will be lowered in discrete steps rather than on a smooth slope. Also in this mode, because is difficult to really know the point at which the media is really saturated you run a higher risk of missing the optimal point (you either replace too soon or too late)
Using a larger amount of media with small amount of water flow insures that the water (again small amount of flow at the start) is completely stripped from phosphate on a continued basis, by adjusting the flow you really gain the capacity to adjust the rate of removal from the total water column by controlling the amount of phosphate free water you are returning to the tank creating a more stable less dicrete way of removal.
Regarding the total amount required of media and why it is so difficult to really know when it can no longer adsorb it is because it depends on two factors the total amount of phosphate to be removed and it's concentration in the water column.
The higher the concentration in the column the higher the amount that the media can adsorb, as the phosphate concentration lowers so does the capacity of the media to adsorb it.
As an example, for Phosban (Rowa isothermal curve is higher) at a concentration of 3 ppm of phosphate in the water colum the Phosban can adsorb about 9 milligrams of Phosphate per gram of Phosban but at a concentration of 1 ppm of phosphate the phosban will adsorb only 6.5 milligrams per gram, at a concentration of 0.5 ppm the adsorption reduces to about 5 mg per gram, at 0.1 ppm to 2 mg per gram and at the final target of 0.05 ppm of phosphate the adsorption is only 1 milligram per gram of media.
In summary the higher the concentration of Phosphate in the water the faster and larger will be the amount removed and the faster the media will saturate requiring a very frequent change of media if the amount of it is small.
If the test kits were accurate enough measuring saturation will be as simple as measuring the phosphate at the output of the reactor, if you measure it is time to replace the media. Unfortunately it has been my experience that normal kits (I have tried Seachem, Salifert, Red Sea and the higher accuracy Hach) the sensitivity stops at about 0.3 to 0.5 ppm of phosphate which is rather high. In theory when your tank phosphate has been lowered by the media below the 0.1 ppm level by the time you detect phosphate in the output you are already accumulating it again. For phosphate testing I now use a Hanna low range colorimeter and even with it I simply to quit trying to measure the reactor's effluent phosphate concentration.
Having said all that, if you were not using a reactor but instead using a media bag in the sump were you can not control the flow then, starting with a smaller amount of media is a must.
After all this talk and trying to de-confuse you
, using larger amount of media with a small amount of flow IMO calls for more continuous better controlled and less cumbersome way of removing the phosphate with lower risk of wasting the media in smaller more frequent changes.Similar threads
