Unsuccessful for three years...

IMO, 5 on nitrates is the least of your worries..concentrate on getting back to basics..keep it simple...personally, I would do water changes every two weeks instead of one massive change at a time and stop dosing all products except calcium and Mg until the water chemistry is more stable...if the collection cup on your skimmer is NOT being emptied at least once a week, then you need to adjust..this could be part of the issue..i would increase the flow on the tank to ensure the skimmer is being utilized fully..if you think test kits are bad, then take a water sample to a LFS for them to check, while u are there I would have them check the TDS of your DI water just to make sure it reads 0..there is one level that was not mentioned..PO4, what is the level?

if you dont have a TDS meter or a PO4 kit, I have both and dont mind testing for you..

2 Koralias2's and 2 of the smallest available forget the number.

This is absolutely one of the biggest factors why you cant grow SPS. Even if you had four K-2's at 600GPH each your would only have a 24X turnover in your tank. IMO a minimum of a 30x turnover is for softies and from 50-100X turnover is good for SPS. For example, I have two K-2s (600GPH each), two Koralia evo 1100's, an evo 1400, and a maxijet 1200 (300GPH) for a total of 5100GPH in my 65 gallon display. A 78X turnover, and I wonder if I need more.

A higher amount of flow will also get more detritous and gunk to your skimmer.
I agree with the few previous comments about your WC's. Smaller ones more often will help stabilize your chemistry and ionic balance a lot. Salt mixes have trace minerals that we don't test for and IMO the supplement your using aren't replacing them. IMO, only water changes can do that unless your buying Iodine, amino acids and a couple other supplements I cant think of right now.

Originally Posted by vinny2261

Grounding probe will save your life!!!!

Isn't that what a GFI is for?

Back to the "unsuccessful" tank - Sometimes it is better to understand the environment one has created and add animals compatible with that environment, rather than trying to get animals to live in an environment that is not ideal for them. In the latter case, the animals will tend to slowly die.

Update:

I added 2 korallia 1400's (1400gph)
changed the return pump to a quiet one 6000 (1000 gph)
so total flow is around 5000 gph

Started doing weekly 25% water changes with seachems salinity salt
levels are more stable. Not having to dose nearly as much.

P04 is and always has been 0
protein skimmer is productive

Started feeding phytoplankton and more coral frenzy.

0 TDS on DI water filter.
I double checked my hydrometer to a local stores and determined it was reading .002 low. So for three years I have had a salinity of 1.028. Problem corrected.

Results: Acan and chalice recession has slowed. Feeders are always out. Mushrooms are no longer popping off their rock. Unfortunately the frogspawn is losing a couple heads every three days. A week and it will be gone. Over a week a large pocillipora colony has lost most of its polyps. Hard to know if it is related to all the changes or some other issue.

A lot of small problems adds up to failure. Overall I think it is heading in the right direction but hard to tell when seeing negative effects on corals that used to be fine.

Sounds like it might be getting on track. grats.

Pocillopora often do a 'polyp bailout' if they get stressed. I would keep your eyes open for little ones beginning to grow around your aquarium

I second frequent water changes, and more flow, but I see you already did that there. I used to have similar problems, but frequent water changes make everything in my tank happy. Replenishes the tank and gets out the junk. Also, how old are your bulbs? I hadn't changed my bulbs in 2 years (time goes by so fast) and we just updated all of them last week... HUGE difference. Everything is brightening up and growing like crazy. Look into BRS Two-Part Dosing. Good luck!

Why feed phytoplankton and coral frenzy? My corals mostly eat fish poo and pee I think lol.

IME, when I used phyto and/or coral frenzy I noticed an increase of algae in the tank...take this for what it is worth...

Have you considered maybe you are getting some heavy metals added? Is there any copper tubing running through the plumbing on your filter unit? I almost made this mistake when I plumbed mine. I also talked to a couple about a year ago who had a lot of tank problems when they started out. What they ended up tracing it back to was the rock they used when they started. They had some lava rock from Hawaii in the tank that leeched heavy metals for years before things stabilized.