Thoughts on root tabs?

I've been thinking about how I'd like to continue to supplement nutrients into my mineralized soil tank as time goes on and I'm wondering how many people use root tabs with success? My growth is still good, but some plants are starting to get holes in the leaves. My tiger lotus, crypt, and staurogyne repens are the most aflicted. I've been told this is due to potassium deficiency?

I see people on eBay putting something called Osmocote in dissolving tablets. They seem cost effective, but don't appear to contain any K.

I've really enjoyed the results from the mineralized soil substrate so far and I'd like to keep the nutrients in the substrate if possible, rather than fertilizing the water column. With that said, I'd love to hear the opinions of the many more experienced aquatic plant growers on this forum.

Thanks in advance.

Hi anderson_p_r,

First of all, are you sure that someone isn't 'munching' on your plants and causing the holes? For example, I had a pleco when I started with planted tanks that just loved to eat holes in some of my plants.

I have used Seachem Flourish Tabs which contain potassium but not any of the Osmocote / Osmocote Plus tabs that you see on the planted aquarium forums and Ebay. That said, the Osmocote Plus product contains 12% Potash (which is potassium).

Yeah, I pulled the mystery snails and there hasn't been a pleco since the tank was setup. I received a small amount of potassium dry fert from a friend and added a pinch or two a couple weeks ago. That seems to halt the holes which lead me to believe it probably was the problem. I remembered reading that the mineralized soil would need potassium about every 6 months, which is about how long my tank has been going.

I just wonder if it's worth it to do a comprehensive root tab like this. My biggest concern is over fertilizing resulting in death of shrimp or plants or algae blooms. The tank is pretty heavily planted and growth continues to do well, but it can't last forever.

Mystery snails don't eat healthy plants, at least I've never had a problem with them.  Some folks claim they do, but I'm not so sure their plants were healthy.

I've never had a problem with root tabs messing with the water column.  If you use them properly (buried) you don't get a lot of nutrient exchange between the root tabs and the water.  I wouldn't worry about it, personally, but it never hurts to put them in a couple of spots and then wait and see if you're nervous about it.

It also doesn't hurt to add some K2SO4 to the water every week.

Wow, weekly? I didn't think they would consume that much. Though I suppose it depends on the dose. I'm considering ordering some on eBay just because of how cheap they are and seeing how the plants respond.

I just started dosing the stuff last week, myself. I'd been using KNO3 and HK2PO4 for a while, but the nitrates and phosphates ran away on me (that's what I get for not regularly testing). So now I'm dosing just potassium (the sulfate apparently doesn't have any ill effect) for a while, counting on the foods I feed to supply adequate nitrate and phosphate levels. I'll test again this week to see how things are going. I never seem to be short on anything else - just potassium, like you - holes in the plants. I'm starting at 10ppm per dose, twice a week.

Well, the root tabs are going well so far. I got some from eBay that contain Osmocote Plus, which has apparently been discontinued. New growth is doing well. No holes in leaves and my crypt's new leaves or holeless and red. I got 150 of them for $10, not bad, though I'm sure I could make myself for less. That is still a many year supply for the little 10g. I'm looking into what alternative Osmocote formulas would be appropriate for the aquarium.

All critters have been unaffected.