Major phosphate issues

[L98-Z]

For many years I've battled basic algae from hair to slime, many times going away... but always coming back with what seemed like greater strength. Despite water changes and countless amounts of GFO, I couldn't seem to win. When I started vodka dosing, I noticed a noticeable change and thought I was winning.

Well, now I'm in the process of helping my girlfriend with a nano tank. I set this take up just a couple of weeks ago and have been doing 40-50% water changes every week. All the rocks and such were pulled from my other tank which has been up and running for years. I'm used to doing 20-40 gallon water changes, 5 gallons is such a breeze. Despite what I did, some corals just didn't look happy.

Today I decided to do a phosphate test. Last water 50% water change was around 5 days ago. Normally I'm not a fan of aquarium tests because they rely heavily on colors... and I'm severely colorblind. Hanna Phosphate checker however works great for me.

I test the tank and it reads .41. Not .04..., no it's .41. I'm baffled, relatively new water, only a few rocks, no fish at all and thus no feeding... yet phosphates are extremely high.

So I wanted to see if it was the rocks in the tank or perhaps my "fresh" saltwater. The saltwater is made using Bulk Reef Supplies 5 stage RO/DI that pours into 35 gallon brute trashcans and then mixed with IO or Reef Crystals salts. Normally it's left heated and inside the brute for a couple days with a few maxijets constantly moving it. Today's test on the "fresh" saltwater read .20 on the phospates. Clearly still way too high.

What's the issue here? The brute trashcan?? The salt? The BRS 5 stage is just a couple months old... It seems awfully high for fresh saltwater. Please help, I'd like to beat this issue once and for all.

 

[Breadman03]

I just read another post about high phosphates with "fresh" saltwater. The poster theorized that the salt might be bad. What kind of salt did you use? Maybe the salt is a common link.

 

[FIREFISHPAT]

Do you have TDS Meter on Ro/Di. If you do test the water before it enters the Ro/di chambers. Nice if you have duel TDS so you can test after di . Than see your readings are. That will tell if your filters and DI needs to be changed. That is where you will find your problem. Last time I put a new DI and that was my problem something was wrong with brand new di filter. Before it enters my Ro/DI its .35 After Di unit its 0.00

 

[L98-Z]

I just read another post about high phosphates with "fresh" saltwater. The poster theorized that the salt might be bad. What kind of salt did you use? Maybe the salt is a common link.

Instant ocean mainly, though I've used alot of reef crystals as well. I actually think I'm using reef crystals right now.

 

[L98-Z]

Do you have TDS Meter on Ro/Di. If you do test the water before it enters the Ro/di chambers. Nice if you have duel TDS so you can test after di . Than see your readings are. That will tell if your filters and DI needs to be changed. That is where you will find your problem. Last time I put a new DI and that was my problem something was wrong with brand new di filter. Before it enters my Ro/DI its .35 After Di unit its 0.00

I do have a hand held and in-line TDS meter. The in-line TDS meter says 0 normally, but I question it's accuracy. I'll do a hand-held TDS measurement here in a second.

 

[L98-Z]

The TDS before RO/DI is approximately 70. After RO/DI it was around 4-6. So not zero, but far better than tap water.

 

[jbannick18]

Sounds like your rock may be leaching phosphates, also that 4-6 tds is not good. It is unknown so you never know what actually comprises that tds.

 

[L98-Z]

I certainly believe that the rocks are leaching phosphates. However, if I'm attempting to reduce it, it's terribly difficult when the "fresh" saltwater is also a bit high.

 

[bertoni]

The DI cartridges likely are shot. I'd remove or replace them, since they might be leaching a lot of ammonia. You could try measuring some of the RO water for phosphate. That might be useful. Also, a second opinion on the test kit might help. Some distilled water should read zero.

 

[L98-Z]

I'll replace the DI membranes I guess. It seems I was just replacing them not long ago.

 

[bertoni]

That might be the sign of some issue with the RO membrane. I'd check the TDS before and after the RO.

 

[L98-Z]

Well those were replaced recently as well actually. I think I may have some extra DI resin, so I'll throw that in tomorrow and recheck.

 

[Randy Holmes-Farley]

Rock and sand certainly can hold a lot of phosphate if it6 has been exposed to very high levels in the past.

I'd look to get the TDS to 0 ppm in the source water, but I wouldn't assume that is the source of 0.41 ppm in the tank unless you are still toppping off but have stopped all export methods you used (such as the GFO).

How much GFO were you using and how often did you change it? Some people seem to think it lasts months, but if phosphate is 0.4 ppm, it may only last a day.

 

[L98-Z]

I'm using PhosGuard. I'm actually probably using too much for such a small aquarium (12 gallons), probably 1-2 cups worth in a filter bag.

How long will the rocks leach? These rocks have been in use for years, they were originally dry rock purchased from Bulk Reef Supply. What's the process in removing all the phosphates from the rocks?

 

[Randy Holmes-Farley]

The rocks will leach until you have stripped it all away. So that means until you have the phosphate concentration low and keep it low.

Did you previously use GFO? How often are you replacing the Phosguard? Like GFO, it will deplete fast at 0.4 ppm phosphate, but I think GFO is a better bet for a variety of reasons.

 

[L98-Z]

I was previously using GFO. I switched to PhosGuard because I felt the GFO wasn't working well enough. I still have a large amount of GFO I can use once the newest PhosGuard is expended.

So .20 Phosphates could be attributable to the 4-6 TDS reading in the RO/DI water?

 

[Randy Holmes-Farley]

GFO works as well or better than Phosguard and doesn't have the aluminum release drawback of Phosguard. Heavy Phosguard use may cause some corals to close up, especially leathers.

Yes, the RO/DI effluent could have that much phosphate. It is rerally desirable to keep the effluent at 0 ppm TDS. It may also have substantial ammonia and silicate at that TDS level.

But again, that isn't really a big amount added to an existing tank for top off. 0.2 ppm, added at 1% daily to replace evaporation only boosts phosphate each day by 0.002 ppm. It would take half a year to reach 0.4 ppm in the tank, even if there was zero export or consumption in the tank.

Moreover, foods will add 10-100 times that amount each day. So in normal circumstances, foods are the source and there is no need for most folks to look further. But in an unfed case, and with heavy rock exposure, those other sources may be significant.

 

[FIREFISHPAT]

Sound like DI is bad. Anything more 0 is coming out RO/DI is sign to change filter or DI. After you change DI make 5 gallon of new saltwater and test that before you do water change. This tell what your salt water mix is and you can see if main tank is leaching. I had same problem it was all in Ro/DI water. Don't forget when you are doing all those water changes you are only adding more phoshate because you are putting more phoshate in the tank with bad DI.. This is where your phoshate are coming in first place....and than adding top off water and it goes up more and more...

 

[L98-Z]

I've changed out the DI resin. It appears to be 0 or 1, not entirely sure. Will check again soon since it's been running for a little while now. Had to order new resin and ordered filters just incase those are shot. Lastly, ordered a couple of inline TDS meters to measure through each setup to see when it begins to fail again.

If 4-6 TDS is this harmful, how in the world did anyone run these setups without an RO/DI unit in the old days?

 

[Randy Holmes-Farley]

I've changed out the DI resin. It appears to be 0 or 1, not entirely sure. Will check again soon since it's been running for a little while now. Had to order new resin and ordered filters just incase those are shot. Lastly, ordered a couple of inline TDS meters to measure through each setup to see when it begins to fail again.

If 4-6 TDS is this harmful, how in the world did anyone run these setups without an RO/DI unit in the old days?

Well, some folks had issues and some had suitable tap water.

That said, running an RO/DI until the TDS starts to rise can give worse water in some ways than the starting tap water itself. That's because certainly things are only weakly bound to the DI. Unfortunately, these include silicate, phosphate, and ammonia. When the TDS starts to rise, stronger bound ions like sodium and chloride can pop off these weakly held ions, putting far more of then into the water for a while.

However, as I mentioned above, IMO 0.1 or 0.2 ppm phosphate in top off water is not necessarily a big problem as most people feed far more than that daily.