An idea popped into my head…

[Fishy888]

Flow is important both with the amount and type, I have a nice strong surge from return and long skinny gyre type pumps on either side. If 4 ft or less length a single gyre works. Set it up to the sine wave function and tune the frequency until you see opposite side of tank’s water level move up and down an inch or so in a rhythmic pattern, will create a rocking movement in the tank and keep stuff from settling on the bottom. That algae looks like if you can get enough horizontal flow close to bottom of tank without picking up sand, it will keep the algae from being able to form. Jebao makes a nice cheap gyre and I believe icecap is if you want to get quality and spend the money for it. Also looked at build thread, do you have more live rock in your sump? It does not look like there’s enough live rock possibly in ratio to water volume. Just trying to recommend things other people haven’t yet, I know how frustrating it is to set something up and it not meet expectations

I think placement of the pumps is part of the issue. I moved the circulation pumps downwards after taking them both apart and cleaning them well. I now have better flow while not losing surface agitation.

I currently have about 40 lbs of rock. I will be adding more rock and coral soon.

My system has been through a lot of unexpected challenges but I feel like I’m making progress. I have reduced phosphates considerably. During the time I ran the LaCl drip my Duncans grew 2 baby polyps. They’re getting bigger each day. I have other corals growing faster too.

I just wanted to make sure I really got my phosphates down to my target of 0.1 ppm. I started at 1 ppm at a minimum per Salifert. The blue color was darker blue than the 1 ppm color indicator. Not a ton darker but enough that I wanted to make sure it I got rid of all the excess.

 

[Fishy888]

I did not follow the explanation of the purpose of the experiment. Would clarify what you want to learn. Thanks!

Since the cyano was taking up all the phosphates along with my chaeto I couldn’t get a reading with my test kit. The idea is that if I could take even a small amount of rock and put it in a bucket with an amount of tank water proportionate to the amount of rock and tank water in the system; then I could get a reading pretty close to what the system’s true phosphate numbers are.

 

[damsels are not mean]

Since the cyano was taking up all the phosphates along with my chaeto I couldn’t get a reading with my test kit. The idea is that if I could take even a small amount of rock and put it in a bucket with an amount of tank water proportionate to the amount of rock and tank water in the system; then I could get a reading pretty close to what the system’s true phosphate numbers are.

You are getting a good reading. There's no phosphate in the water. That's what test kits tell you. If phosphate sequestered inside algae or coral or anything else counted towards the total, then a tank full of corals must be super high in phosphate by your logic?

 

[Fishy888]

You are getting a good reading. There's no phosphate in the water. That's what test kits tell you. If phosphate sequestered inside algae or coral or anything else counted towards the total, then a tank full of corals must be super high in phosphate by your logic?

I see your point. My understanding has been that algae in enough quantity can give a false 0 ppm reading but the rocks sequester the high phosphates. I’m posting a link to the article that gave me this idea.

https://reefkeeping.com/issues/2008-07/nftt/index.php

 

[I never finish anythi]

I’ve officially stopped dosing Phosphate-e. It does look like cyano so I’ll treat it as such. It certainly can’t hurt. It also means I don’t have to dose anymore LaCl. Less is more in this situation. Thank you everyone. I appreciate it.

Ch CK out sunnyx is thread on cyano

 

[Randy Holmes-Farley]

I see your point. My understanding has been that algae in enough quantity can give a false 0 ppm reading but the rocks sequester the high phosphates. I’m posting a link to the article that gave me this idea.

https://reefkeeping.com/issues/2008-07/nftt/index.php

To call it a "false' reading is misleading. There are many sinks and sources of phosphate, and none are false. It's all just a matter of how you interpret the real measurement.

 

[damsels are not mean]

I see your point. My understanding has been that algae in enough quantity can give a false 0 ppm reading but the rocks sequester the high phosphates. I’m posting a link to the article that gave me this idea.

https://reefkeeping.com/issues/2008-07/nftt/index.php

Well, something's going to use nutrients as long as there is no other limit to growth of those things. Test kits for nitrate and phosphate can only tell you that you have a running surplus of nutrients that the system is unable to utilize. If you have a new tank with a bunch of bare rock ready to be colonized by algae, then there is no other limit to growth and nutrients will be taken up very quickly. A mature tank full of corals has very little space for anything to grow and utilize those nutrients except the corals themselves, which grow much more slowly than algae. So you would expect to read very low or even 0 nutrients in a new tank all the time until stuff grows in. OF course if you let the whole thing become a block of algae you'd see nutrients climb again.

 

[Dan_P]

Since the cyano was taking up all the phosphates along with my chaeto I couldn’t get a reading with my test kit. The idea is that if I could take even a small amount of rock and put it in a bucket with an amount of tank water proportionate to the amount of rock and tank water in the system; then I could get a reading pretty close to what the system’s true phosphate numbers are.

Got it!

The experiment could tell you how much phosphate could be coming off the rock sample. From this you might infer that it is too small to detect once it is diluted in the aquarium water BUT at the surface of the rock it might be a significant transient blast of phosphate, which could be feeding local nuisance organisms.

I did this with aquarium sand and was able to measure an increase in PO4 when I mixed sand with freshly prepared Instant Ocean.

Give it a try. You might find the project to be interesting.

 

[Fishy888]

Well, something's going to use nutrients as long as there is no other limit to growth of those things. Test kits for nitrate and phosphate can only tell you that you have a running surplus of nutrients that the system is unable to utilize. If you have a new tank with a bunch of bare rock ready to be colonized by algae, then there is no other limit to growth and nutrients will be taken up very quickly. A mature tank full of corals has very little space for anything to grow and utilize those nutrients except the corals themselves, which grow much more slowly than algae. So you would expect to read very low or even 0 nutrients in a new tank all the time until stuff grows in. OF course if you let the whole thing become a block of algae you'd see nutrients climb again.

All this is true. I just wanted to know how much may still be bound up in the rock itself.