3 months ago my tank turned 1yr and I had an algae problem. I had monitored PO4 with Hanna tests at the LFS once a month. In the first 9 months they ranged from 1.6 to .06. NO2 and NO3 have always been very close to zero. With a relatively busy summer I missed testing for a couple months. I still kept up with bi-weekly 10 - 20% water changes but it was not enough. PO4 test in late October showed 2.36 and I had a lot of algae growing. So I started an aggressive PO4 reduction program. Perhaps too aggressive as a few days ago PO4 was zero. I've been told I must have some PO4 for the corals unless I go ultra-low nutrient and start dosing amino acids. LFS says their SPS stock displays are usually .04 - .08. I've always heard .06 or below is good. LFS says they tend toward .08 to more closely match average customers levels.
I'm not sure how my levels got so high. I had been keeping up on water changes with RO water from LFS and if anything was feeding less. Two months ago I purchased an RO/DI system. No more paying for water and lugging buckets! My suspicion is the RO from LFS wasn't exactly perfect. If that's the case it's no longer an issue. Maybe I was feeding to much, but I hadn't really changed the amounts. If anything was feeding less leading up to the huge PO4 number.
At this point, I guess I'm happy that I was able to reduce the PO4. Even if I went to far. Algae is gone except for a little on a couple of base rocks I couldn't remove and scrub. Emerald crabs and other cleanup crew are slowly removing what's left. Went from cleaning glass almost daily to every 4 or 5 days. Corals including Duncans, Zoas, Slimer, leather and a couple of small sps frags seem to be doing fine but I'm concerned that won't be the case long term if PO4 stayed at zero. So what's a good way to get PO4 to more reasonable levels? I know nothing about ULNS (ZEOvit?). Is it reasonable to attempt in a system with fish? I'm assuming I can just feed more and cut back on PO4 removal methods to get levels up.
Here's my plan. Any feedback is appreciated:
1. Feed more.
2. Carbon dosing reduction. Slowly taper off the booze. I worked up to 1.5mL/day on 65 gal. system volume over the past couple months. Going to cut this back by 5% each week for next 4 weeks and evaluate further reduction.
3. Reduce my DIY GFO reactor flow/add no new GFO to reactor. It's currently running at approx. 90gal/hr. Going to cut flow to 60gal/hr.
4. Macro algae: I added some to the sump 2 months ago. It quickly doubled in mass first few weeks - when PO4 was high and has not grown since. Still looks healthy so I'm just going to leave it in place.
5. Algae scrubber: Going to leave this in place. It's grown just a very little since I installed my DIY unit 3 months ago. I never had a good pump to feed this so the flow is very slow maybe 10 gal./hr. I've never had too clean it off.
As I start to get more into SPS corals I'm focused on keeping the system stable and making no drastic changes.
Other parameters:
65gal total system volume
dKH averages 7.5 - 8.5 w/manual drip dosing of 1/2 tsp. soda ash/day
pH: don't test often but always 8.2 or 8.3 when I do
NO2/NO3: test once a month and always zero or very near
Salinity: 1.026
Calcium: Been running kind of high as much as 520 a month ago now at 460-480. LFS says not to worry and attributes to doubling up water changes (20% weekly) with Instant Ocean Reef Crystals when I first started on PO4 reduction. I have not dosed calcium for about 2.5 months.
I'm not sure how my levels got so high. I had been keeping up on water changes with RO water from LFS and if anything was feeding less. Two months ago I purchased an RO/DI system. No more paying for water and lugging buckets! My suspicion is the RO from LFS wasn't exactly perfect. If that's the case it's no longer an issue. Maybe I was feeding to much, but I hadn't really changed the amounts. If anything was feeding less leading up to the huge PO4 number.
At this point, I guess I'm happy that I was able to reduce the PO4. Even if I went to far. Algae is gone except for a little on a couple of base rocks I couldn't remove and scrub. Emerald crabs and other cleanup crew are slowly removing what's left. Went from cleaning glass almost daily to every 4 or 5 days. Corals including Duncans, Zoas, Slimer, leather and a couple of small sps frags seem to be doing fine but I'm concerned that won't be the case long term if PO4 stayed at zero. So what's a good way to get PO4 to more reasonable levels? I know nothing about ULNS (ZEOvit?). Is it reasonable to attempt in a system with fish? I'm assuming I can just feed more and cut back on PO4 removal methods to get levels up.
Here's my plan. Any feedback is appreciated:
1. Feed more.
2. Carbon dosing reduction. Slowly taper off the booze. I worked up to 1.5mL/day on 65 gal. system volume over the past couple months. Going to cut this back by 5% each week for next 4 weeks and evaluate further reduction.
3. Reduce my DIY GFO reactor flow/add no new GFO to reactor. It's currently running at approx. 90gal/hr. Going to cut flow to 60gal/hr.
4. Macro algae: I added some to the sump 2 months ago. It quickly doubled in mass first few weeks - when PO4 was high and has not grown since. Still looks healthy so I'm just going to leave it in place.
5. Algae scrubber: Going to leave this in place. It's grown just a very little since I installed my DIY unit 3 months ago. I never had a good pump to feed this so the flow is very slow maybe 10 gal./hr. I've never had too clean it off.
As I start to get more into SPS corals I'm focused on keeping the system stable and making no drastic changes.
Other parameters:
65gal total system volume
dKH averages 7.5 - 8.5 w/manual drip dosing of 1/2 tsp. soda ash/day
pH: don't test often but always 8.2 or 8.3 when I do
NO2/NO3: test once a month and always zero or very near
Salinity: 1.026
Calcium: Been running kind of high as much as 520 a month ago now at 460-480. LFS says not to worry and attributes to doubling up water changes (20% weekly) with Instant Ocean Reef Crystals when I first started on PO4 reduction. I have not dosed calcium for about 2.5 months.