Growth has become sluggish

[rhodesengr]

I have a planted tank that I have been running for a number of years. It seems that the growth has become sluggish where I used to get pretty decent growth. It must be a water condition issue but I am not sure what to look for or measure or how to fix it. Here is my setup

36 gallon tank
fresh water at about 77 degrees
pressurized CO2
Eheim classic filter
55W AH supply light 6700K lamp
Dose with micro and macro ferts and have tried Excel on and off

I am thinking maybe there is too much debris in the substrate but it seems hard to clean with rooted plants. can too much organic material in the gravel cause sluggish growth. Why would this be? I think to clean the substrate, I'd have to yank all the plants out. Open to any and all ideas. Is there something I can test for? Maybe Nitrate level? Would high Nitrate cause sluggish growth? I would think it would cause fast growth.

[Wasserpest]

I don't think high nitrates would cause sluggish growth, although there can be interactions where high levels of one thing reduce the ability to process other nutrients. You could perhaps measure the NO3 and see if it is in the normal range?

You can do a deeper cleaning of the substrate without un-planting and taking everything out. Use a gravel vac get some good suction that swirls around the gravel and removes some of the debris. It is conceivable that too much debris leads to an overall reduction in beneficial micro-currents within the substrate that carry nutrients to the roots.

Often it is one or more nutrients that are depleted. You haven't specified which macros and micros you are dosing, and how much/how often, so I am assuming this is all good.

You might want to do a few large water changes, and do the substrate cleaning and a good thorough pruning of your plant mass and see if this revives them. If not, I would start to look at the nutrients (incl CO2) and see if there is a problem somewhere. Perhaps try a different micro mix, etc.

[evan.m]

Is that a flourecent light? I hear they degrade, as far as intensity, over time. Maybe you just need some new bulbs

[Bluek24a4]

Maybe you have such an increase in plant mass that you need to be dosing more to get the same growth rate as before.

More plants using the same resources as before = less to go around = slowed growth rate.

[rhodesengr]

Bulbs are new. They have burnt out and been replaced several times.

I took all the old plants out and put in some new ones. Plant loading is very light

I am basically doing EI dosing. Potasium Nitrate and Potassium Phosphate are my macro solution. I add Potassium sulfate at the water changes. Changing 50% per week.

CSMB is my micro solution.

Just tested Nitrates and looks to be about 20 ppm

[Kyrol]

substrate?

[rhodesengr]

sea chem flourite. The red stuff. I was think about just starting over and put ADA in the tank. But for one thing its expensive and Flourite was supposed to be a good substrate. So I thought i would post and see if I can figure out what the real problem is.

I should add that right next to the tank in question, I have a 26 gallon tank set up for fancy goldfish. The CO2 system, lights, substrate, filter, and ferts are exactly the same. This other tank has a single giant anubias plant that grows like gang busters. My problem in the second tank is not sluggish growth but diatoms. Anyway, the equipment is fine

[Bettatail]

old tank syndrome?
if it is old tank syndrome, the PH is too low (too high or too low the plants suffer), check your water PH.

[rhodesengr]

pH is 7.3 with CO2 off on a digital pH meter.

I read up on old tank and it sounds like it applies more to fish than plants.

My fish are fine. Some of them are years old.

[aquarist]

You can also try getting some root tabs and putting them into the substrate, you may also want to dose some iron. Most plant substrates come packed with Iron and other nutrients and over time your plants will use it all, so you may want to try adding some iron and seeing how that goes.

As stated above a good gravel cleaning would also be a good idea, you should not have to take out any of the plants just clean around them, if there is no space around them then you may have to take a few out.

Also it's a good idea to give some of your substrate a turn every once in a while, about once a month I turn the substrate in my planted tank you only want to do about one quater of the free space, not a quarter of the entire surface, just what isnt cover with plants, turn over the top 1/4" of the substrate, so what used to be on top is no longer on top, I just use a spoon to do this, only takes about 5 minutes to do it in my 75 gallon. Be careful not to turn over too much substrate at one time though because you may cause a mini-cycle. I like to mix my substrate up for three reasons: it helps bring any decaying matter up to the surface for easy removal, it releases gases that are produced from decaying matter and may be traped below the substrate, it also prevents your substrate from becoming compacted and will allow plants roots to grow throughout the substrate much easier. Also if you decide that you want to mix some of your substrate up, it is a very good idea to do it during a water change, that way you can remove any gases that are released.

If you have an abundance of decaying matter in your tank you may want to pick up a good cleaning crew for your tank, fish like catfish make good cleaners, just research your fish first to make sure they do don't get too large. Snails and shrimp are also a good choice for a clean up crew, I personally don't know a lot about shrimp but I haven't had any luck keeping mine around for long. I get about 20 ghost shrimp from the LFS every few months and they always slowly disappear, I suspect my fish are eatting them but I never see them do it. There are a bunch of snail choices out there, at first I was going to suggest that you get a few MTS but if you have a lot of detritus in the tank you might end up with more than you had bargained for. If there is not a detritus problem than MTS would be a great choice, they naturally burrow into the substrate so if you have a large enough population they can help keep the substrate nice and lightly packed.

[pejerrey]

I •believe• that:

If there is enough nutrients and co2, plant growth rate is determined solely by the light intensity.

[OVT]

You are experiencing what I run into several years ago - flourite run out of nutrients, Regardless of the manufacturers' claims, it becomes inert after about 10 years.

[Wasserpest]

Flourite doesn't provide much in terms of nutrients to start with. There might be some iron and other micros, but not enough to support years of plant growth. That said, adding some root tabs or fert sticks or capsules near rosette plants can give them a good boost in growth.

[Sotty]

Originally Posted by aquarist

You can also try getting some root tabs and putting them into the substrate, you may also want to dose some iron.

This was the suggestion I got years ago after continually running a heavily planted hi tech tank for a few years. I had been doing EI for the water column but had never used root tabs. I also had flourite and many at the time thought my flourite might have run out of iron and that the amount of csm+B I had been dosing wasn't enough (I did not see an obvious signs of iron deficiency). I increased my iron dosage by about 1/3 and started doing root tabs throughout the tank every other week.

Plant growth notably picked up over the next several months, unfortunately then real life got much busier and I had to leave the planted tank world for several years, so I can't comment on long term results.

[rhodesengr]

Originally Posted by Sotty

I increased my iron dosage by about 1/3 and started doing root tabs throughout the tank every other week.

Is there a root tab product everyone is using?

I'd like to change over to ADA Aquasoil but it seems I'd have to take all my fish out of the tank for a few months and I don't really want to set up another tank just to fix this one.

In the short term, I am going to remove the plats and aggressively clean the gravel by vacuuming and turning it over. I have never done that with this tank. I guess I can do that while the fish are in the tank. Then I'll see if that helps, if not then I'll start the ADA conversion.