Phosphates in newly cycled tank

[CatsandClowns]

Hey, y'all, I just set up my 20-gallon AIO a month ago. After a fishless cycle, I read 0 ammonia and nitrite. I added fish a week after that. They have been in there for about one week with no issue(aside from them, ive got a few snails and some hermits, no corals or other yet).

I have been testing ammonia and nitrate every other day without any fluctuations. Alkalinity @ 7.15 dKH, Magnesium @ 1485 ppm, Calcium @ 400 ppm, pH @ 8.1, Nitrate between 5 and 10. My main concern is that the Phosphate reading was very high @ 0.78 ppm using a Hanna ULR Phosphate Reader. This, however, was within 24 hours of my weekly water change. Additionally, I clean the rear chamber every water change, as well as clean/replace filter media, and I use RODI water from my LFS(considering they use that same water in their low-phosphate systems, I highly doubt the filters in their systems aren't replaced regularly). Finally, on the topic of feeding, I use TDO Chroma Boost Pellet food, and often have very little uneaten food.

Since this is my first time checking phosphate levels, I have no way of knowing the trend before today. My question is, do water changes, siphoning sandbed/rocks stir up inorganic or organic phosphates that make it more sensitive to the Hanna checker within a certain period (24-48 hours)? What else might I be doing that could contribute to such high phosphate levels? Other than just wait and see, are there other possible solutions? I would rather avoid GFO or any more harsh alternatives if possible. Thanks in advance!

 

[edsbeaker]

Hi,
That’s a bit high on the phosphates, especially considering that you’ve only had fish in there for a week. In a newer system, I wouldn’t think that there should be that much unless the water from the LFS has phosphate or you are feeding too much.
You may want to test the water that you are getting from your LFS as a first step. If phosphates are 0, then it may be overfeeding.

TDO chroma boost is a fantastic food, but like all pellets, can result in high phosphate. It’s very nutrient dense food, and you need surprisingly little to feed the fish. Even if the fish are eating it all, the fish still poop it out into the water.

How many fish do you have in the tank?

 

[Fish Fan]

Phosphate can also be bound to, and then released in to the water, by some rocks. Depending on the rock you used, you may be seeing some of that here.

@edsbeaker hit the nail on the head though, usually high phosphate has something to do with what you're feeding.

Good luck!

 

[CatsandClowns]

Hi,
That’s a bit high on the phosphates, especially considering that you’ve only had fish in there for a week. In a newer system, I wouldn’t think that there should be that much unless the water from the LFS has phosphate or you are feeding too much.
You may want to test the water that you are getting from your LFS as a first step. If phosphates are 0, then it may be overfeeding.

TDO chroma boost is a fantastic food, but like all pellets, can result in high phosphate. It’s very nutrient dense food, and you need surprisingly little to feed the fish. Even if the fish are eating it all, the fish still poop it out into the water.

How many fish do you have in the tank?

Hello! I have two clowns in the tank. If the fish waste would be the main thing contributing to elevated phosphates in my case, I don’t see why it would be so high.

 

[edsbeaker]

Phosphate can also be bound to, and then released in to the water, by some rocks. Depending on the rock you used, you may be seeing some of that here.

@edsbeaker hit the nail on the head though, usually high phosphate has something to do with what you're feeding.

Good luck!

That is a good point with the new rock, especially if it was dry.

 

[Fish Fan]

That is a good point with the new rock, especially if it was dry.

Yes ma'am! We don't know what the OP was using for rock, so I just wanted to offer that as a possibility.

Thank you for your reply!

 

[MikeReefs]

not sure what rock you have but Dry rock usually have phosphate and they leach into the water. This is why most people cure it before adding to their tanks. GFO can be used to bring it down. Ease into it though, start will less the recommended dose. Eventually the rock will release all the phosphate

 

[edsbeaker]

Hello! I have two clowns in the tank. If the fish waste would be the main thing contributing to elevated phosphates in my case, I don’t see why it would be so high.

Yeah, with only two clownfish, even with a bit of overfeeding, that phosphate is really high for that to be the only reason. I tend to agree with @Fish Fan that the rock could also be leaching phosphates.
Did you start with Dry rock?

 

[CatsandClowns]

not sure what rock you have but Dry rock usually have phosphate and they leach into the water. This is why most people cure it before adding to their tanks. GFO can be used to bring it down. Ease into it though, start will less the recommended dose. Eventually the rock will release all the phosphate

I did begin with dry rock so you all may have answered my question there. However, would GFO even make a difference considering the rocks may continue to leach phosphate afterward? Or rather they would continue to leach phosphates regardless, and my only method of export would be GFO and more frequent water changes until those levels decrease to an acceptable range.

 

[edsbeaker]

I did begin with dry rock so you all may have answered my question there. However, would GFO even make a difference considering the rocks may continue to leach phosphate afterward? Or rather they would continue to leach phosphates regardless, and my only method of export would be GFO and more frequent water changes until those levels decrease to an acceptable range.

The GFO, (as long as you keep up with replacing it as it becomes exhausted), will take care of the high phosphates as the rock releases more of it. It will take some time for the rock to be depleted of the phosphates, and once that happens you may be able to stop using the GFO.

More frequent water changes can also help if you really don’t want to use GFO. It’s just a different way of exporting those phosphates, but I think that would be a lot of work and saltwater.

 

[CatsandClowns]

I did begin with dry rock so you all may have answered my question there. However, would GFO even make a difference considering the rocks may continue to leach phosphate afterward? Or rather they would continue to leach phosphates regardless, and my only method of export would be GFO and more frequent water changes until those levels decrease to an acceptable range.

The GFO, (as long as you keep up with replacing it as it becomes exhausted), will take care of the high phosphates as the rock releases more of it. It will take some time for the rock to be depleted of the phosphates, and once that happens you may be able to stop using the GFO.

More frequent water changes can also help if you really don’t want to use GFO. It’s just a different way of exporting those phosphates, but I think that would be a lot of work and saltwater.

I don’t mind a mix of both but I’ll take it slow. Will likely go buy some in the morning. Thanks everyone!