It sounds like you do have quite a heavy PO4 issue so use whatever you need to.

I think you've hit it on the head.
Without consistent rock and sand cleaning I guess her PO4 is built up and now releasing.

OK, now I am confused because I was always told not to disturb your sand because you would just create issues in your tank. I have a conch that has always done a good job. I think that I am having issues now because my R/O was reading 10 on my tds meter and I was dumping in .22 of phosphates every time I was adding fresh water or doing a change. I have that solved now so I am hoping that eventually I will get my phosphates under control again.

Don't be confused, I think you are on the right track. Just keep changing your Rowa until the PO4 for stays down

And cleaning the sand, it just means the surface, not going deep into it

OK, thought I missed the boat somewhere along the way!! Yes, in the directions it does say the rowaphos may be used up in a few days in the begining so I guess it is not that unusual.

Well, it was a bit of an experiment for my tank and I'm only a few weeks in but the results came quick. My issue was my NO3 was undetectable, and my PO4 was too as long as I used GFO. As soon as I ran out of GFO my PO4 would skyrocket fast but NO3 would stay at 0.

Wish I had more time to go further in depth, but start with the basics: weekly/bi-weekly water changes including vacuuming the sand and blowing off the rocks, good skimmer, don't let uneaten food sit, rinse food before feeding, good cleanup crew, etc.

It appears that an imbalance between nitrates, phosphates, and carbon will cause cyano as it was a constant fight in my tank.

First I started feeding the fish and corals a lot more than ever. PO4 raised quickly (over .2ppm) and eventually finally NO3 slowly started coming up. Then I resumed dosing carbon and bacteria. I use prodibio. I'm sure MB7 or the like with vodka or sugar would work too. Make sure you read on the proper way to dose carbon before you start.
Then I started to dose NaNO3 to bring up my NO3 to around 2ppm. As soon as it got high enough I had a bacterial bloom and the next day my PO4 was .02ppm without GFO! All I've had to do is keep my NO3 between 1-2ppm and it keeps the PO4 down.

I'm hoping I can keep this balance moving forward without having to dose NaNO3 on a regular basis, but we'll see. It is extremely cheap if I do end up having to dose.

The idea is bacteria need to consume nitrate, phosphate and carbon. I was putting plenty of bacteria in the tank, giving them lots of carbon and phosphates, but they were starved for nitrates. As soon as I gave them more nitrates they gobbled up the phosphates. Then my skimmer started pulling out some pretty thick and stinky skimate!

Good write up with some useful advice, it's a fine balance we run with our tanks, and they let us know when we're not in check, like cyano or algae and other blooms.

I agree that siphoning with a gravel cleaner about 1-2" of the top layer every week is going to help lots with getting those phosphates and nitrates down. Just do a small section every week. Also before doing wc blast a section of rock with powerheads and return off then let it settle on the sand bed and siphon out, as long as you don't blast the coral itself it should be fine, sps can take a blasting. I use a maxijet 600 with hose on it to get into the rockwork to blow the crud out, although I have bare bottom whatever settles can be pooled in the back and is easily siphoned out.

Good luck keep on it and give us updates...

You mentioned the tds and no3 on your rodi, how often do you change the prefilters on it? Also do you change the di resin frequently?

I only run carbon and ro on mine as some have said di is not needed, also the water here in Vancouver is quite clean. I changed my prefilters every 8 months but now have been changing it every 6 months.

Wow, that is super interesting! I have stopped using any carbon in the last 6 months because my coral beauty got hole in the head and is super sensitive to it. Not sure if that may be contributing to my issues but it is interesting how I have almost no nitrates as well. I am assuming you are talking about regular carbon or is there is a different kind I have missed? How are you adding the carbon and how much are you using? I am just a little hesitant to use carbon and risk losing my fish. I just have one spot of cyano in one of my lower flow areas but it is obviously telling me things are not balanced like you are saying.
Tang daddy mentioned about my R/O water. We have really bad water quality where I live, so bad we don't drink it from the tap and have boil water advisories often. We decided to get a Culligan water system so we could hook it to our fridge and also for the tank. I did not realize that the water quality would not be as good as my cheapo R/O unit I got from J & L. It was okay in the begining but after changing all the filters again I was still getting 10 on the tds meter and my NO4 coming out was .22. The membrane was $170 bucks and I still wouldn't have really had really great water so I went back to my old one. I think this is what has really messed up my tank.

He's talking about a carbon source not black charcoal for water clarity. A carbon source will feed bacteria. A example is np pro by aquaforest with this you would be feeding bacteria that will help reduce phosphates and nitrates your bacteria source would be aquaforest pro bio-s. I'm using aquaforest as a example there's many other carbon and bacteria products.

Yes, thanks. I was assuming it was not regular carbon for water clarity. Never stop learning about new things when issues arise that you haven't had to deal with yet. So is this a better way to deal with high phosphates then?

Even after changing the filters you are getting bad tds this is odd as the ro membraine would be stripping the water clean one would think....

I am almost 💯% certain it's your water that is adding to the phosphates, you may want to try to add some nitrates and carbon source "slowly" to see if it helps bring down the phosphates. As Warriorcookie has mentioned he had to add nitrates in order for his phos to drop down as they play hand in hand dragging each other down.

So if you only have a lot of one and none of the other then that's where the imbalance is and alsolock your phos where it is and not allowing it to drop lower. Rowa phos will cost you and arm and leg if you have to change it weekly.

Maybe try a brightwell bio brick and add some nitrates to help bring your phos down. You can also try reef biofuel and wet skimming as a carbon source. Any adjustments you make do it slow and watch your tank close for any I'll effects.