[jbjonas]

We've had a low tech planted tank for 2.5 years. For the last 2 years we've kept the same dosing schedule and our plants have done excellently and algae has been really well controlled. All of a sudden over the last 2 months many of our plants' growth has suddenly been stunted and algae growth has increased all around. I think we need to adjust our dosing, but I have no idea what to change. Finding the balance we've kept for the last 2 years was difficult trial and error in the first place... I'd be grateful for any suggestions.

The tank is a 46 gallon bowfront, 40 gallons of water with a deep substrate of mixed sand, small gravel, and fertilizer (CaribSea Flora Max Planted Aquarium Substrate). The fertilizer is 2.5 years old, but there seems to still be plenty of it.

The light is not super strong but has worked great all this time, on about 8 hours a day. None of the LEDs have burned out, and since it's not fluorescent I'm thinking the light output hasn't changed just because it's older?
see:{www.amazon.com/Aquatic-Life-Aquarium-Fixture-48-Inch/dp/B00H3Y4YLW}

Our Dosing:
-DAILY:
-- 5ml Seachem Excel
-2x WEEKLY:
-- 10ml Seachem Flourish Comprehensive
-- 20ml Seachem Flourish Potassium
-- 25ml Seachem Flourish Phosphorus
-- 5ml Seachem Flourish Nitrogen

Every 2 weeks we do a 50% water change (religiously). We use tap water, but that's been the same all this time as well. Perhaps one variable is that the tap water could have changed, I know.

In the last 2 years we've never had anything but 0 Ammonia, 0 Nitrites, and our pH has been stable around 7.9.
After every water change our Nitrates are about 5ppm, and after 2 weeks and 4 doses they are never higher than 10ppm right before the next water change.

In the last 2 months algae has gotten worse, but the most noticeable changes are that the following plants have stopped growing well. By this I mean that they have slowed their rate of growth and show much more algae accumulation on the leaves. I don't see anything that might point to a specific nutrient deficiency like holes in the leaves, curling, or yellowing - but perhaps I don't know what to look for:
- Swords
- Staurogyne repens
- Rotala
- Hortwort
- Clinopodium Cf. Brownei

Strangely, these plants are doing great and still growing as rapidly as they always have:
- Ludwigia Repens
- Vallisneria

Here are 3 pictures from 2 months ago, 1 month ago, and today.

I'm really lost as to what might have changed to cause this. I'm hoping some of you might have helpful experience and suggestions. Thanks so much!

 

[Seattle_Aquarist]

Hi jbjonas,

Is the PH of your water currently 7.9?

We use tap water, but that's been the same all this time as well. Perhaps one variable is that the tap water could have changed, I know.

I would suspect that is the situation. The characteristics of the tap water have probably changed. Why? Remember all that rain and snow that hit the Sierras last winter and ended the drought? It is likely that all that snow melt and rain (both of which are very soft water) have diluted the mineral content of your tap water.....possibly substantially.

So I download the first and last picture and blew them up. I think this problems was likely occurring in August but has worsened in the last month. As best as I could make out the margins of the Ludwigia repens leaves (did not see any Staurogyne repens) show signs of chlorosis (yellowing) and the leaf margins are rippled or scalloped. Both older and newer leaves. I would suspect a magnesium (Mg) deficiency but it is likely your calcium also dropped with the dilution of the reservoirs the provide a lot of the water in So. CA.

I would add Seachem Equilibrium, 1 teaspoon per 10 gallons will increase your hardness by 2.0 dGH and add calcium, magnesium, potassium, iron, and manganese. I would do it twice the first week. Thereafter add 2 teaspoons once a week when you do your 20 gallon water change. Then for the next two weeks watch your new leaves as they emerge (the leaves that are already there will change very little if any). Do the new leaves look greener, healthier, little to no scallops on the leaf margins? Has the overall growth improved? If so then you are on the right track. If the plants look better but some deficiency symptoms are still exhibited you can add a little more (maybe 1/2 teaspoon per 10 gallon) and see how things look after another couple of weeks. Do not change anything else. Leave the light intensity, photoperiod, and dosing of other nutrients exactly the same....what we want to see what the effect of the extra magnesium and calcium has on the new growth. If questions just ask! -Roy

 

[Surf]

Flourish comprehensive is deficient in nitrogen, questionable on Phosphate, magnesium, sulfur, and chlorine. for southern california I would expect your water to moderate to hard due to the colorado river water that is imported. Some of your water is imported from northern CA but that is generally soft water. You are probably fine on nitrogen, potassium, and phosphate due to those being dosed separately. Last winter the Sierra nevada mountains received about 200% of normal rainfall in only about4 months. There probably was also an increase in rainfall in the Colorado Plateau. Your tap water might be softer now than before and have less chlorides and sulfides in it. Might also have less magnesium. You could try adding some Epsom salt and maybe some sodium chloride table salt to increase magnesium, sulfur and chloride lovels. But I don't know how much you would need without knowing what is in your water.

You would likely be safe adding only 2 degrees (about35ppm) worth of magnesium sulfate and 3ppm sodium chloride. You can use a nutrient calculator to help ermine how much to add.https://rotalabutterfly.com/nutrient-calculator.php

You might also want to look at your water utility water quality report on line and or call the utility and ask if there have been any changes in the last 4 months or so. Specifically ask about magnesium sulfur and chlorides. Note the water quality repot you see on line is likely 6 months old or more.

Also if you have a deficiency micro nutrients excess might be present. Excess micro nutrients can sometimes slow plant growth or become toxic plants and animals. So I would do at least 4 water changes without flourish comprehensive but still dose NPK,Mg,S to get micro nutrient levels down. Also during each water change remove as much algae as possible and deep clean the substrate to reduce organic material AND nutrient buildup in the substrate.

Note sometimes nutrient deficiencies don't show any obvious visual symptoms other than slow or no growth.

 

[Deanna]

I'd take it slow and do things one at a time then wait a few weeks to see if things change. First do what @Seattle_Aquarist suggests. In the meantime, get a GH test kit (API GH test kit is $9 on Amazon). That will tell you if your hardness (combined calcium and magnesium) is good (above 4 degrees) and help you determine how much Equilibrium to add on a regular basis once it settles down.

If that doesn't work, I'd then start looking at what @Surf is suggesting: a balancing of ferts, although you were content with what you've been doing for over 2 years. In any case, probably a good idea to make sure your ferts are balanced well and the Rotala Butterfly calculator is good, but you'll have to cut the dosages at least in half because you don't inject CO2. You can gauge dosages with your nitrate and phosphate tests (API phosphate test kit is $11 on Amazon). I'll bet you find the phosphate to be high because you are way-overdosing the Flourish Phosphorus.

The algae is probably due to the deteriorating plant health. When plants are healthy, algae is inhibited.

Just had another thought: the Flourish (formerly Flourish Comprehensive) has to be refrigerated within 3 months of opening. If you didn't do that, and are sitting there with 2-year old Flourish, it may have fermented or become contaminated with mold.

 

[jbjonas]

Thanks everyone! Your suggestions make a lot of sense. I've ordered some Seachem Equilibrium and an API KH/GH test kit. Once I get them I will take a GH level before doing anything else, but I think I'll follow the suggestion from @Seattle_Aquarist first without making other changes and observe for a few weeks.

I just did a pH test and the tank is at 8.1. This is on the high side for us, as the tap is typically between 7.8 and 8.0, but if there have been recent changes to the water supply I'm not surprised if it's currently slightly higher...

One thing I forgot to mention is that we have always been adding about 30ml (2 tablespoons) of API Aquarium Salt with each 20 gallon water change. This was just for general fish health and we've been doing so for 2.5 years. When we recently had a pleco and some otos die we decided to cut that in half, as I read salt might not be very good for catfish types, but it was only last week that we made that change. I always thought that such a small amount of aquarium salt wouldn't effect our plants (and never seemed to so far) but I'm welcome to your opinions on that as well.

As far as dosing the Equilibrium, I will plan to start adding 10ml (2 teaspoons) with each 20 gallon water change, starting with our next change in a week. It sounds like you suggest adding the same amount 2x the first week? So should we dissolve 10ml in a small amount of water and add that to the tank early this week - and then add the same regular amount with each water change thereafter? I think that's what I understood you were suggesting. I suppose another thing to decide is whether to continue adding the aquarium salt as well for every water change...

Thanks - I'm hoping this will help resolve our issues.

 

[Seattle_Aquarist]

Hi jbjonas,

I think your problems will be resolved without too much hassle.

I agree, when you get your test kit first take a 'baseline' reading so you know where your are starting; write it down. Then after your next water change add 4 teaspoons of Equilibrium; that should increase your hardness by about 2.0 dGH. Wait a week and during the following water change add 4 more teaspoons of Equilibrium; that should increase your dGH to a total of 3 degrees above your baseline. Thereafter when you do your water changes add 2 teaspoons to the 20 gallons of new water being added. Equilibrium has a tendency to 'cake', it is easier to dissolve it in warm water and then add it to your tank. Or, if you are old school you can just add it directly to the tank and look at white chunks until it dissolves. I started with aquariums about 6 decades ago, we used non-iodized or rock salt in our tanks for ''General Health" then as well. I haven't done that in years and I don't believe my fish are any worse off than when I was dosing salt.

 

[Deanna]

I would cut the salt out altogether. There is nothing good about it for the plants and can be detrimental to them. Corys are certainly very unhappy with it. I think the fish health aspect (I, too, remember doing it many decades ago) is an old wives tale, like phosphates cause algae. It has been indicated for treatment of disease purposes, but you can create a healthy environment for your fish without the salt.

 

[jbjonas]

Another question that came to mind. Will adding the Equilibrium to change the dGH also effect the pH? We want to fix the issues with our plants, but not at the expense of our fish of course. Our pH has always been high at around 7.8 - 8.0, but our fish are also used to it being pretty stable there. I'm not all that familiar with the chemistry, but I thought there was a relation between hardness and pH and don't want to go changing things that might have a detrimental effect on the health of the fish.

Thanks.

 

[Deanna]

Another question that came to mind. Will adding the Equilibrium to change the dGH also effect the pH? We want to fix the issues with our plants, but not at the expense of our fish of course. Our pH has always been high at around 7.8 - 8.0, but our fish are also used to it being pretty stable there. I'm not all that familiar with the chemistry, but I thought there was a relation between hardness and pH and don't want to go changing things that might have a detrimental effect on the health of the fish.

Thanks.

No: Equilibrium will change GH, but not pH or KH.

 

[jbjonas]

Thanks @Deanna. It sounds like the Seachem Equilibrium is our best bet as the first thing to try and is pretty safe as far as no ill effects for our fish population

We still have a debate going in the household as to whether we should discontinue adding the aquarium salt... We've been doing it for so long, and at what we thought were pretty low doses (1 tablespoon per 10 gallons for a long time, and recently half that much). When you research it on forums there seems to be a wide variety of conflicting opinions. One thing we have had trouble with over time is keeping Corys, and Otocinclus. We also had a beautiful Longfin Albino Bushynose Pleco who was healthy for nearly 2 years and then died suddenly this month... who knows if that was related to the same issue that appears to possibly be tap water fluctuations.

Not to change the topic of this thread, but I wonder what people think about salt and our issues with different varieties of catfish. I had read that certain scaleless fish like catfish can be particularly sensitive to salt, but again there's so much conflicting advice out there... I'm beginning to think that if the health benefits of regularly dosing salt aren't clear, perhaps it's not worth it, even if the detrimental effects aren't 'proven' either.

 

[StevieD]

As in all things it is a case of how little and how often. Ian Fuller is a world renowned expert on Corydoras and he says a little salt is not harmful but again it depends on how much is a little.

Having bred several species of Corydoras and treated sick ones, some successfully and some not I would tend to leave the salt out of the picture.

Then again opinions are like elbows, most people have two!

 

[Deanna]

Ultimately, with most of these things, you'll have to use your own judgement because, as you found, there are a million different opinions for any given issue. The problem is that the only truly statistically valid studies (requiring a minimum of 30 tests just to BEGIN to be statistically valid) must be performed by companies able and willing to do so. It's just too expensive to set up a minimum of 30 tests with each test having identical parameters. Our hobby isn't big enough to drive such things. There are companies that do it, such as Seachem, and then they come out with some products that address what they targeted, but most other 'evidence' you find here is based upon anecdotal experience. So, you end up going with those opinions that are consistently dominant through time. An example would be our now predominantly believing that phosphate doesn't cause algae.

 

[DennisSingh]

A question to ask has ur substrate gone anaerobic, do u see sulfur bubbles popping out and smell sulfur?

 

[jbjonas]

Thanks @StrungOut, but no I don't see any bubbles in the substrate or smell anything unusual like sulfur. Why do you ask that?

 

[jbjonas]

We got our test kit today and I've carefully tested our aquarium water. I repeated both tests a couple times to get familiar with them (we all know how imprecise the API kits can be).

To the best I can determine, these are our current readings:
GH = 9 dGH
KH = 5 dKH

So what should we do now? In 2.5 years we've never measured these. I can offer that aqadvisor.com with all our fish entered says "Recommended hardness range: 5 - 15 dH" whatever that means...

We're going to wait for guidance before adding any Seachem Equilibrium, which also arrived today. Thanks everyone!

 

[Seattle_Aquarist]

Hi jbjonas,

Just follow the suggestions in post #6 of this thread; take some pics in a couple of weeks of your new growth and let's see how things are going. In answer to your question in post #8, Deanna is correct there should be no increase in your dKH since you are not dosing anything with carbonates in it.

 

[jbjonas]

Thanks very much for the encouragement. The community on this forum seems very knowledgeable and patient...

I followed your suggestions @Seattle_Aquarist and added 4 teaspoons Equilibrium, which as calculated should have raised the tank by 2 dGH. The actual measurement I took an hour later had gone up 3 degrees to 12 dGH, but I suppose that's about as precise as one can expect from the API test kit. Seems like a good result!

I also measured the hardness of our tap water, which matched exactly what I had taken as a baseline for the tank water - so that's reassuring.

We'll keep an eye on the plants, follow your suggestions again when we do our next water change, and of course report back here. Feeling optimistic so far - thanks again everyone for your help!

 

[burr740]

Seriously doubt you need Equilibrium with a GH of 9, but it probably wont hurt anything. Since you've started down that road might as well ride it out and see if it helps.

In my opinion the substrate is probably out of nutrients after 2.5 years. I'd give the sword a couple of root tabs, double the Flourish nitrogen and increase the rest by maybe 50%.

Fwiw API Nitrate tests are notorious for reading high. Unless you've compared the results to a known solution 5-10 could easily be 2 or zero. So you might try just increasing the nitrogen first and see if that helps. Its the most likely suspect.

As the plants grow the overall biomass increases, which means a greater need for nutrients and everything else. Although the tank is not that heavily planted, the principle remains. What was enough nutrients a few months ago may not be enough today, especially if the substrate has expired.

The fact that the vals and ludwigia are the only plants doing well is a red flag for a nutrient shortage - because they are hungry fast growers. If that sounds contradictory, think of a pack of wolves or lions on a fresh kill. The strong eat first, the weaker competitors cant get in there to begin with. They have to wait around for scraps. I think in this case there's not enough scraps left over to go around.

 

[Deanna]

Fwiw API Nitrate tests are notorious for reading high.

Agree on the API nitrate test. Not so much reading high, but just impossible to determine in the most common range of 10-40. I greatly prefer the Salifert nitrate test.

However, I have calibrated the API GH/KH and API phosphate tests and found them to be as accurate as can be for a titration test.

 

[Seattle_Aquarist]

Hi @burr740,

Fwiw API Nitrate tests are notorious for reading high. Unless you've compared the results to a known solution 5-10 could easily be 2 or zero. So you might try just increasing the nitrogen first and see if that helps. Its the most likely suspect.

I agree we should all be cautious about test kit results, and inaccurate nitrate and phosphate readings can certainly cause issues if they are off substantially. However, I purchased a new API Test Kit (btw folks always check the expiration dates on the reactant bottles) with 2020 expiration dates on the bottles; mixed up a 100 ppm solution of KNO3 using distilled water and and a gram scale, then cut the 100 ppm solution with distilled water to 20 ppm, 10 ppm, and 5ppm. The results were that the API Nitrate Test Kit were right on the money (as good as my old eyes could tell).