I've stopped dosing Phosphates

[Fishyfanatic]

I had a really bad stint with brush and blue/green algae about a month or two ago. It overran my tank and caused me to have to toss almost all of my plants. I tried to salvage as much as I could but in the end I just tossed all except for one type. It turned out that the phosphates were maxed on on the test kit and Nitrates were barely reading. I stopped dosing Phosphates entirely and now dose a higher amount of Nitrogen (a heaping 1/2 teaspoon every other day). I still dose Plantex CSM+B every other day. Is it bad that I stopped dosing the Phosphates? I tested the tank yesterday and had 2.0 ppm Phosphates and 10 ppm Nitrates. I'm going to up the Nitrates to try and get that 1:10 ratio. Right now I'm having an issue with the brush algae coming back. I also increased the CO2 a little bit. Any comments?

 

[Purrbox]

I don't think that it's bad that you stopped dosing Phosphates, as long as you keep an eye on it and start dosing again before it bottoms out.

 

[Fishyfanatic]

I stopped adding the Phosphates when the outbreak originally occured so it's been at least a month without dosing. I just wanted to make sure my tank wasn't lacking anything by not adding the phosphates.

 

[Plantbrain]

Well, this assumes that your test kit is correct for both PO4 and NO3.
I seldom here of folks calibrating any of these cheapo test kits, so that accuracy is debatable.

Thus so is the confidence in such readings.
BBA, brush algae and BGA all have nothing to do with high PO4 anyway.

BGA= the low NO3 caused that.
BBA= lower/variable CO2 caused that.

See any PO4 in there?
No...........

So has the tank done better because you stopped adding PO4 or is it due to you adding NO3?

If you dose based on a test kit measurement, you need to be sure the test kit is accurate over the range of interest.

NO3 and PO4 are the worst, well, Fe is as well, of all the test kits for accurate readings.
You can make a reference standard and measure the test kit against a known solution.

That way you have confirmed it's accuracy/inaccuracy.
Then you may dose based on a confirmed accuracy.

Otherwise you many as well just estimate the NO3/PO4 reading and do some water changes to prevent high levels and dose frequently to prevent anything from running out. Then you do not need such test kits, you can estimate the effective range easily.

News to many, but test kits are by no means particularly accurate, and have a lot of assumptions.

Adding to that, the bioindicator species such as BGA, BBA etc tell a far different story and conclusion. No one to date has ever shown that either is caused by high PO4.

No one.

Regards,
Tom Barr

 

[Fishyfanatic]

Right now my Nitrates are higher than they have ever been. Normally it barely registers but now that it is reading 10 ppm I am having issues with BGA again. At any rate no harm in not dosing the Phosphates. Thanks Purr.

 

[Lonewolfblue]

The way I got rid of my BGA when my 29G was infected was through 2 things, first cleaning the tank well and adding lots of AC to the filter and doing a 5 day blackout. Then when this was complete, I increased my nitrate dosing. BGA has never returned. But on a previous blackout, it did come back. Why? Kept dosing the same nitrates. And even though my test kit read nitrates, it must have been dropping out. My BGA is now gone for good.

 

[Fishyfanatic]

Thanks Lone. I'm going to up the Nitrogen a little bit more and see how it goes. I just wanted to make sure that my plants wouldn't be lacking anything by not dosing the Phosphates. I take it they won't so no need to dose.

 

[Purrbox]

As long as you're getting enough phosphates through your water source and food, you wouldn't need to dose. Once you get your ferts balanced out I've got a feeling that the phosphate uptake will increase to the point where you need to begin dosing again. I would recommend that you start dosing again before your phosphates actually reach zero. It sounds like you want to get your Nitrates to 20ppm and keep you Phosphates at 2ppm, so if your Phosphates start to drop below 2ppm you would want to start dosing.

 

[Fishyfanatic]

I've been monitoring the phosphates but as I add plants and they grow I'll definitely keep an eye out for it to bottom out. I may be making a rather large order in a few weeks so I'll be sure to test daily.

 

[Plantbrain]

You folks are still assuming those test kits are correct.
You still base the dosings on their readings.

Suppose that 10ppm on that test kit is really 2ppm, or 5ppm.
Suppose the PO4 test kit is measuring just total PO4(They all do, (the hobby kits) after all) and not the bioavailable forms from KH2PO4? Suppose that reading is really 0.4ppm and not 2 ppm?

How can you answer that/these question/s with any confidence?
Faith? Pray they work?

I suppose...........

Calibrate them, mix up a solution of 5 ppm for PO4, 40ppm for NO3, make a liter at a time and then dilute a sub sample of these with DI water. Then you can make a series of 5ppm, 10pp, 20ppm, and 40ppm for NO3.

Do the same for the PO4 over the range, 0.2 ppm, 0.5ppm, 1.0ppm, 1.5pp, 2.0ppm etc

Then you no longer need prayer to hope that the test kit is right, note, this still does not tell you if the fraction of is bioavailable, there's plenty of organically bound N and P floating around tanks.

By doing large water changes, that removes all that. Then you add inorganic ferts and can be assured that you have at least that much based on a simple dosing calculator.

Merely because you added some KNO3 does not imply that BGA will go away, I never said nor told you that.................

I said it can prevent it from coming back.
Reducing NO3 will induce BGA, you already have a an algae issues, you have to kill what's there first, see above post, 3 day blackout will do.

Then you dose thereafter top prevent infestations.
20-30ppm is a better range for NO3 and 2-3ppm for PO4 for plant growth.

These are easy targets to dose using a dosing calculator and water changes.
No test kit issues or other assumptions are brought into the tank this way.

It's simple and folks already do water changes.

If you do test and want to correlate algae blooms, then you need to start with an otherwise healthy tank and then remove the NO3 or CO2 etc.

Otherwise you have no control, so a tank that already has algae is a bad tank to use to do test on, there's no control and it could be a dozen different things.

You lack the control and test methods to say much about the tank.
The algae do not lie, the test kits when not calibrated etc, most certainly do.

Note, I'm not trying to give you a hard time, many aquarist think that because they have high PO4 or NO3 etc and they have algae, it's due to that.

But that's simply not true.

If you do a control test, use proper methods, you cannot not induce either algae with high PO4, nor with high NO3.

Once an algae is there, the best way to handle it, is kill/remove what is there and make sure the plants have the right conditions to grow well. Otherwise the algae just keeps coming back again and again. Then you wasted all the labor and effort removing the algae.
Focus should be on the root cause, then and rest of algae management is easy.

So focus on the plants and algae will no longer be much of an issue for you.

Few get into this hobby to learn how to kill and grow algae, nor to enjoy using test kits near as I can tell yet many lose sight of the real reason they got into the hobby, to grow plants, so focus on that, not test kits, not killing algae.

Regards,
Tom Barr

 

[An t-iasg]

How is your CO2 holding up? I see in the first post that you said you increased it a little. You have pressurized now, right? When I got my pressurized system, it did take a few weeks to get used to the system and figure out where I wanted set my pH meter to get the desired CO2 concentration. I also dose the EI method as best as I can (a 10 gallon was a little tricky to figure out at first, but I've got it now). I did do testing every day for about 10 days to see the relationships between all the nutrients. I noticed that the phosphate was used up by half, in one or two days, as the CO2 stablilized. So watch carefully and don't be surprised if your phosphate level takes a dive suddenly. I dose enough P so that I don't bottom out. I test once a month now (or whenever I think of it!) My P levels are 1.5 -2 and my nitrate is between 20 and 30 ppm. That's the best reading I can determine on that color strip (Seachem tests) for nitrates. Everything in the tank seems fine.

 

[Fishyfanatic]

An t-iasg- Yes, I'm on pressurized CO2. Considering it's a 55 gal tank I didn't want to have a lot of 2 liter bottles set up for DIY. It's hard enough keeping my cats away from the CO2 tank, I couldn't imagine having a bunch of bottles around the tank (we have an open stand). I'm going to stick with my plan for a few weeks and wait to see the results. I also cleaned the diffuser yesterday and I think that was causing a problem with the CO2. i didn't realize how much beard algae was inside of that thing until I took it apart. It's running smoothly now. For a while there when everything was in check the plants were growing beautifully. Then this past week the BGA started to make a return but I'd like to stop it before it gets out of control. Only time will tell.

I may move the diffuser to the center of the tank. I've noticed that on the other side of the tank is where the algae is really growing. Could it be a lack of CO2 on the other side of the tank or is it just coincidence? I'd also thought about putting a power head inside to help with circulation.

 

[Purrbox]

You folks are still assuming those test kits are correct.
You still base the dosings on their readings.

Nope, just assuming that Fishyfanatic is already following your advice to calibrate those test kits. Probably just as bad of an assumption when it comes down to it.

If it were me, I'd give the powerhead a try. Since the algae seems to be localized to one area of the tank, it defiantely seems to indicate that there is a nutrient distribution/flow issues.

 

[An t-iasg]

I think the powerhead is a good idea too. I had awful BGA until I used a little pump (you can't call it a powerhead in a 10 gallon tank, lol) to suck up and blow around the little CO2 mist bubbles. I can post a picture later if you want. Your 55 gallon will be a little different but you'll get the idea.

The Seachem tests I have do have a reference solution, and I do use it once in a while.

 

[Fishyfanatic]

I'll add the power head during the next water change and reposition the diffuser. I never really thought about it before but yesterday it dawned on me that most of the algae cleanup has been on the left side of the tank. The diffuser is on the right side of the tank and I hardly ever have algae over there. And it might be that I just need to reposition the filter output but I think that the powerhead would be a good idea anyway to help with circulation.

 

[Plantbrain]

How is your CO2 holding up? I see in the first post that you said you increased it a little. You have pressurized now, right? When I got my pressurized system, it did take a few weeks to get used to the system and figure out where I wanted set my pH meter to get the desired CO2 concentration. I also dose the EI method as best as I can (a 10 gallon was a little tricky to figure out at first, but I've got it now). I did do testing every day for about 10 days to see the relationships between all the nutrients. I noticed that the phosphate was used up by half, in one or two days, as the CO2 stablilized. So watch carefully and don't be surprised if your phosphate level takes a dive suddenly. I dose enough P so that I don't bottom out. I test once a month now (or whenever I think of it!) My P levels are 1.5 -2 and my nitrate is between 20 and 30 ppm. That's the best reading I can determine on that color strip (Seachem tests) for nitrates. Everything in the tank seems fine.

These numbers are in line with test and general results using this method.
Even if they are not calibrated, the results(the lack of algae and good growth) suggest that both comparative methods are likely correct.

2ppm PO4, 20-30ppm of NO3, good CO2, etc, no algae, good plant growth.

I could not tell anyone what to do, dose, or much of anything if I'd started dosing/testing based off of a faulty kit that gave me poor results that I assumed where right.

Depending on the test kit, I'd have to assume that no NO3 might be optimal if it was 20ppm off, maybe test kits are off by that much as well.

Regards,
Tom Barr

 

[Plantbrain]

I may move the diffuser to the center of the tank. I've noticed that on the other side of the tank is where the algae is really growing. Could it be a lack of CO2 on the other side of the tank or is it just coincidence? I'd also thought about putting a power head inside to help with circulation.

Try blasting the mist length wise in the tank.

If you want to test a localized area that has BBA, try directing the mist to that location and removing the BBA that's there now.

You should not see any new BBA form if you blast the mist into certain sections, but get BBA elsewhere in the tank.

Such patterns are telling, they suggest that you do not have have enough CO2............

Which if you look back, is what I suggested to start with.....

So both the low NO3 and the low CO2 are highly related to the BGA and BBA respectively.

You have a good plan, just take those test kits readings with a large grain of salt..........focus on dosing good KNO4, KH2PO4, Traces, maybe GH, doing large weekly or 2x a week water changes, then prune out all that nasty algae, trim it off, clean the equipment that has it on there, vacuum up any BGA, harass that algae.

As the plant health increases, the algae will decline.

You are not too far off, just be patient and attack it.
You should dose after each water change and then 1-2x more during the week or just dose after each 2x a week water change.

More water changes will not hurt and will help most any tank, dose there after. Observe tank after water change etc.

Also, try and do the water change in the early part of the day, maybe 1-2 hours after the lights come off.

Note pearling.

Regards,
Tom Barr

 

[An t-iasg]

Fishyfanatic,
Hopefully these pictures will help you set up a "mist apparatus" from your powerhead. I placed my pump directly above the glass diffuser. The pump's intake was directly over the diffuser, so that the pump gathered in all or most of the CO2 that was leaving the diffuser. The pump then blew the CO2 all over the tank. You can see in the picture how the tank looks with tons of little CO2 mist bubbles. My pump directs water on the short side of the tank. Since your tank is bigger, follow Tom's suggestion of having your powerhead direct water lengthwise through the tank. My tank is so small that it didn't make a difference - the mist still goes everywhere.

 

[Fishyfanatic]

My setup is quite a bit different than yours. My diffuser is not like that at all. Tomorrow morning before I go to work I'll take pictures and post. Thanks for your help.

 

[corster]

How do you have no alge?