SPS irritated when I try to raise alk above 6.5 dkh????

[jlinzmaier]

I've kept my alk at 7.5 dkh using only kalk dosing and everything seems to be happy. I'm finally getting good growth rates and good polyp extension from my SPS at night. I do have trouble with silicates in my ro/di water (even with new resin) so I'm going to upgrade to a second DI filtration component with a different type of DI resin than I'm currently using. The fact that silicates are coming thorugh makes me wonder what else is coming through so a second type of DI resin seems like it would be worth the cost and effort.

Jeremy

 

[KrazyOnetime]

I know from direct experience with a similiar issue where I could not go above 7/8 or so depending on the test kit, when I was used to 10/11dkh with extraordinarly fast sps growth. I have found that running "ULNS's" you MUST maintain a lower alk or the stn/rtn happens. try looking up info on running low nutrient systems. 6 is low. I've also found leaving risiduaql amounts of phosphates (3) and nitrates (5-10) helped. Still haven't figured it out completely. it's been 1 1/2 yrs

 

[KrazyOnetime]

With silicates you'd have tons of diatoms possible cyno if there wass avalable phosphate.