MTS causing my deficiency symptoms?

[7Enigma]

Hello everyone,

I routinuely get deficiency symptoms that causes my staghorn algae to make a play for my plants. My anubias leaves, Rotala mac., java fern, and stargrass at seemingly random times suddenly get this.

I do weekly 50% PWC's and dose ferts routinuely. My symptoms don't match anything exactly and I've waffled from a potassium issue, to a magnesium or calcium issue. My GH is ~10 so I originally had ruled out Ca/Mg, but I'm starting to really wonder if one or the other isn't deficient.

I am still on DIY CO2 but have the 2 bottle system going which should keep relatively stable levels of CO2.

I'll be switching back to a 50/50 bulb which should reduce my light level from ~4wpg to ~2wpg which should alleviate both some of the deficiency/algae, and my work level of pruning so frequently.

But on to the question. Ever since feeding with my own frozen mixture my MTS population has exploded. I originally started my 10gallon QT tank for plant trimmings but moreso for snail production. That is no longer the case as I have TONS of baby and mature MTS, so much so that they are visible even during the day. I had heard previously some anecdotal evidence that a large population of snails can strip the water of its Ca due to shell formation, and wondered if its possible they are consuming so much calcium (along with the plants), that my every other day dosing of calcium sulfate (1/4 teaspoon into 20 gallon tank) is just not enough to hold out the week before my 50% PWC.

I seem to notice that my algae problems are lessened after the PWC which would seem to me to be due to a lessening of dissolved organics, or due to adding back in something no longer in the water (namely Ca/Mg). I dose the full complement of ferts so unless there is some trace element in very short supply in the water that is NOT in the CSM+B, I can't see what it could be. I do have an old bottle of Flourish Comprehensive that I might start dosing mid-week to see if its some trace element that the CSM+B doesn't supply, but that's a shot in the dark.

Fortunately I had a small amount of hygro that I put back into the main tank that is growing very quickly, and should help as an indicator plant to see if my changes are helping.

But I'm looking for some opinions on whether the snails could be the cause of this problem.

For reference here's my dosing schedule and setup:

20gallon high tank
65w CF 6700k (soon to be replaced with a 50/50 bulb)
DIY CO2 with powerhead mist dispersion (2 2L bottles changed out bi-weekly, ie one this week, one the next)
50% weekly water change
PFS substrate (possible cause?)

At water change:

-1/2 tsp potassium
-1/2 tsp magnesium
-1/2 tsp calcium
-slightly less than 1/4 tsp CSM+B
-1/2 tsp baking soda per 5 gallons of tank water (for KH buffering)

day after water change (and every other day):

-~1/32 tsp phosphate

days when phosphate is not dosed:

-~1/32 tsp CSM+B

between 2-3times a week:

-1/4 tsp potassium

-1/4 tsp magnesium/calcium

NitrAte is NEVER added due to high bioload (nitrAtes have never been under 20ppm)

Thanks for the help.

 

[Purrbox]

I would expect that a large snail population could easily cause Calcium Difficiency issues. This would be especially true if your water supply is already short on Calcium and you were having to dose in order to keep the plants happy in the first place.

 

[7Enigma]

That's my thought as well. I've been stumped the last couple of months since I seem to have everything in excess and yet I'm getting deficiency symptoms. And with my 50% PWC per week I have a hard time imagining its due to a nutrient toxicity.

Any chance the baking soda could be a cause? I've started to slowly lower it down to ~3/4 of a 1/2 tsp per ~5 gallons from the full 1/2 tsp. I use the same bucket to remove the water that I use to put it back in so water in = water out. Any water I add during the week is only dechlorinated, no other ferts/chems are added to prevent concentration.