I feel your pain, buddy! Hahaha. It isn't until you've run a 12 wk cycle of Test/Deca/Dbol that you REALLY know the pain of calve or lower back pumps. In part, it's something you just have to get used to, but you can work toward holding less water. We want to hold some on cycle when gains is the goal, but when it gets to the point that you can't walk into the gym without needing a break before your first exercise, something most be done. 

Theres a chance that your blood pressure is getting higher with all this fluid, so first things first, find a cuff that will fit around your bicep and make sure that you're close to 120/80. If you're higher than that, you'll need to keep an eye on it, through this process. You may not feel high BP, but believe me, long term will do a number on your kidney function. It won't take long to do damage that can't be undone. So here are some thoughts. 

First of all, I'm going to say what might be my catch phrase...Diet is key. Look at your sodium intake. Its easy to get a ton of salt in your diet when you are eating so much food each day. See where you can reduce it. Gear will increase sodium retention making water retention worse than when you are clean. 

Next, pound the water. The more water you drink, the more fluid you will release. I would suggest that you drink at least 1 gallon a day. Proper hydration will also help with your muscle gains and injury prevention. 

From here, look at estrogen control. You need an AI on cycle to control estrogen and keep it in the normal range. As an added bonus, it will help keep more of your test from converting to estrogen, thus having a higher test level. You don't want to take it too far, as low estrgen can cause it's own set of issues. Dosing is different for everyone but a good place to start is around .5mg adex, EOD, for an average dosed cycle, say 500mg test, 400mg EQ.

Cardio will help too. Get a good sweat going, improve your cardio health and increase your appetite. I stay covered up on cardio and try to sweat as much as I can. Plus sweating is a good way to release toxins through the skin. If your goal is currently muscle gain, keep it slow, walking on incline for 20 min post workout a few times a wk. 

Last, if you are really having issues with this, you can start the process out by taking a mild water pill. There are natural herbal diuretics out there, or you could go the pharm route, using something mild like 1 tab of dyazide in the moring, for a couple of days. BUT don't use this as your primary means of water control. Long term, diuretic use can cause more problems than benefit. So even if you take this step, make sure that you are doing everything else right first. 

Best of luck, bud. As far as problems go, too big of a pump is a good problem to have. ;)