Need help with Phosphates!!!

Crocpete · Jun 13, 2019

i have been battling different types of algae since I started my tank 8 months ago. Green hair and cyano being the most common. I had high nitrate levels but finally got that under control with NOPOX. Out of the blue my phosphates shot up to 3ppm and I can’t get it down no matter what I try! It’s been over 2 months and the algae is a daily struggle and I have lost a few frags. I am getting to the point of throwing in the towel and giving away what’s left. I am not buying any more filtration: I currently only have a small skimmer and HOB filter that I tried to add GFO too but I don’t think it really worked. Any info or advice is appreciated, thank you.
It’s a 20 gal tank with about 15 lbs live rock and 2” deep sand bed. Only 2 fish and a few zoa frags

w2inc · Jun 14, 2019

Do you do any maintenance on your sand bed? Do you have any reason to think the sand bed might have been collecting sediment?

Is there a chance that there is a big dead snail in there some place.

Is your skimmer productive? Do you feel like it is taking out plenty of stuff.

Higher alkalinity makes skimmers work better. Kalkwasser is a pretty easy add. Should bind some Phosphate as well as make your skimmer work better.

Check your GFO on the way in and on the way out of your reactor. There should be a change if things are working well.

I have a refugium that helps me balance things out but it sounds like that is not an option for you. My tank that has no refugium has no sand. I do think sand has a good potential to act as a nutrient sink and I have seen a Po4 rise inside a week that I blamed on a sand bed.

How much bio load do you have?
How stable is your pH?
How much control do you have over your lighting?
Have the NO3 and PO4 levels ever been at a "normal" place for you?

ihavecrabs · Jun 14, 2019

Crocpete said:
i have been battling different types of algae since I started my tank 8 months ago. Green hair and cyano being the most common. I had high nitrate levels but finally got that under control with NOPOX. Out of the blue my phosphates shot up to 3ppm and I can’t get it down no matter what I try! It’s been over 2 months and the algae is a daily struggle and I have lost a few frags. I am getting to the point of throwing in the towel and giving away what’s left. I am not buying any more filtration: I currently only have a small skimmer and HOB filter that I tried to add GFO too but I don’t think it really worked. Any info or advice is appreciated, thank you.
It’s a 20 gal tank with about 15 lbs live rock and 2” deep sand bed. Only 2 fish and a few zoa frags

Yeah 3ppm is a little high. GFO will work. Did you add it to a bag or a media canister? The latter works a lot more effective and efficiently exposing the media to more water.

I would say that Phosphate is not the only cause for your algae issues though. Keep in mind your young tank is still maturing and the bacteria, algae, macro/microfauna are all battling for their place and will eventually stabilize. The algaes tend to need some manually assistance with removal (best because you don't want it dying in the tank).

If you were to take phosphates way down fast, I suspect it will upset whatever balance exists today and throw stability up in the air again.. May make things worse.

Go slow with GFO and shoot for the 1ppm range for now. That is my opinion and recommendation.

#reefsquad to give you some more recommendations or other ideas!

Lasse · Jun 14, 2019

First important question: What do you measure your PO4 with

Sincerely Lasse

Dr. Reef · Jun 14, 2019

First off we need to rule out human error and or bad test kit.
Once it's clear that those 2 issues dont exist then if 3ppm is really a true level, then lanthanum chloride will be a very effective way to reduce phosphate.

Crocpete · Jun 14, 2019

Thank you very much for the responses. I have a very small bioload, only one ocellaris clown and a tail spot blend. I have 3 mini colonies of zoa's that are actually thriving and growing. I lost 3 other mini colonies though and a hollywood stunner. The cleanup crew is small; a few nassarius snails, some blue legged hermits and a serpent sea star. I do have a good amount of snail poop and detritus that i blow off the rocks with the baster and try to get it down to the sand bed where i hope it gets taken care of. I have siphoned so much cyano out of the tank that my sand bed is lower by an inch!!! I have removed the rocks and scrubbed them down 3 times. A refugium is not an option and Im not really sure about how to do the GFO. I have a simple HOB filter that I put the GFO in a filter bag and stuffed it in there but I think it just blocked and prevented the filter from doing its job. The skimmer is really small and needs to be dumped twice a day! My numbers are all pretty good, the pH is usually around 7.8 but i feel like my NO and PO have always been either really high or nonexistent. I have been testing everything with Red Sea.

Lasse · Jun 14, 2019

With this desciption - my backbone says fault measurements/bad test kit - try to confirm it with another test kit (or for PO4 - a Hanna test)

Sincerely Lasse

w2inc · Jun 14, 2019

Crocpete said:
Thank you very much for the responses. I have a very small bioload, only one ocellaris clown and a tail spot blend. I have 3 mini colonies of zoa's that are actually thriving and growing. I lost 3 other mini colonies though and a hollywood stunner. The cleanup crew is small; a few nassarius snails, some blue legged hermits and a serpent sea star. I do have a good amount of snail poop and detritus that i blow off the rocks with the baster and try to get it down to the sand bed where i hope it gets taken care of. I have siphoned so much cyano out of the tank that my sand bed is lower by an inch!!! I have removed the rocks and scrubbed them down 3 times. A refugium is not an option and Im not really sure about how to do the GFO. I have a simple HOB filter that I put the GFO in a filter bag and stuffed it in there but I think it just blocked and prevented the filter from doing its job. The skimmer is really small and needs to be dumped twice a day! My numbers are all pretty good, the pH is usually around 7.8 but i feel like my NO and PO have always been either really high or nonexistent. I have been testing everything with Red Sea.

I have to agree with @Lasse on being sure that your test equipment and technique is on. Generally speaking, I have to agree with him on the majority of the comments I have read from him.

If you have a LFS near by that tests water for customers then go see if their measurements are really close to yours. If your test kits are off, it would be really nice to know a this stage of the game.

I couldn't make a PO4 test kit work for me until I gave in and bought the Hanna. Turns out that my PO4 was about 10x higher than my other brand kit was showing. I feel good with my kits for the other parameters I test, but the results from phosphate is just hard to read and many of them have such a large range that they are not that useful to me.

Skimmer twice a day sounds frustrating. If you can adjust it to skim drier then it might save you a little anguish.

I didn't see your alkalinity level and for me, that one is kind of the backbone. pH of 7.8 when the lights first come on is a level that I am comfortable with. The same level when the lights are about to go off is something I would want more information about. The two values follow each other to an extent. Take a look at your ALK and pH tonight and let us know what they look like.

Do you keep bio-media in your filter, or is it just a GFO holder?
Is your filter your primary water flow or do you have an additional circulation pump?

fish farmer · Jun 14, 2019

What is your water change schedual like? I would be blasting those rocks and siphoning out what you can. I would think you should be able to get those phos numbers down a bit with some WC, if the numbers are accurate. How much do you feed?

Crocpete · Jun 15, 2019

Ok, my latest numbers were: Calcium - 360, Mg - 1200, alkalinity - 9.6 dkh & specific gravity of 1.025. I feed flakes every other day, reef roids 2-3 times per week & mysis once a week. I don’t have a reactor so I just put some GFO in a mesh bag and put it in the filter. I have to top off probably every 3 days, and I have slacked big time on the water changes as I felt it wasn’t making a difference & I wasn’t getting any res

fish farmer · Jun 15, 2019

Keep up on those water changes, making sure to pull what algae you can during those changes. I would also boost up your clean up crew, get turbo snails and/or trochus snails. I recently bought 4 smallish Mexican turbos for a red algae problem in my 29 gal, they took most of it away in a months time. Don't throw a ton of snails in, just add a few.

w2inc · Jun 17, 2019

Crocpete said:
Ok, my latest numbers were: Calcium - 360, Mg - 1200, alkalinity - 9.6 dkh & specific gravity of 1.025. I feed flakes every other day, reef roids 2-3 times per week & mysis once a week. I don’t have a reactor so I just put some GFO in a mesh bag and put it in the filter. I have to top off probably every 3 days, and I have slacked big time on the water changes as I felt it wasn’t making a difference & I wasn’t getting any res

If your top off water is not RODI or distilled, then you need to make that change. On a system like yours where skimming and GFO are the only phosphate export, it is important to keep up with a regular water change schedule. IMO, GFO in a bag is fine. I don't feed my coral as a normal practice, I have a couple LPS but mostly SPS. I have fed in the past but I have only seen it directly effect my Chalice. If you want to back down on your nutrient input to the tank, maybe consider cutting the coral food out or down to once a week until you get your PO4 in check.

I prefer to keep my calcium and magnesium levels up to the 400 and 1350 range. Higher magnesium is connected with slowing the growth of some kinds of algae. Water changes with salt that is really high in these areas will boost it a little, but I typically just manually dose the tank until my levels are where I want. From that point it will be easier to tell if your water change schedule will maintain them.

Your DKH is in a fine place for me, but the trend these days is to keep I under 9 if you are going after a low nutrient system.

Kalkwasser might be a good next option for you as far as keeping calcium levels and pH up as well as pulling phosphate out, (or just binding it and making it unavailable).

Sand beds can be a reservoir of PO4. IMO, pulling it out is a drastic move but could be a realistic no cost solution if other things don't work. I would syphon it out in sections with my water changes, but not pull it all out at once.

Here is a link to a video about adding Kalkwasser. It is by Julian Sprung. He has written some really influential books on the hobby and been around it since the 80's. He has simplified using it to simply adding a spoonful of powder into a glass of water and dumping it into your tank. He speaks more directly about the PO4 binding abilities at about 5 minutes into the video and continues on to talk about safe amounts to use and how.